diff --git a/.github/workflows/build.yml b/.github/workflows/build.yml
index c5ce48712c..976f4c47c7 100644
--- a/.github/workflows/build.yml
+++ b/.github/workflows/build.yml
@@ -25,7 +25,9 @@ jobs:
         uses: docker/setup-buildx-action@v3
       - uses: actions/setup-java@v3
         with:
-          java-version: 11
+          java-version: |
+            17
+            11
           distribution: 'zulu'
           cache: 'gradle'
       - name: Prepare build variables
@@ -72,3 +74,28 @@ jobs:
           tags: |
             "${{ env.CONTAINER_REGISTRY }}/${{ steps.build_variables.outputs.REPO }}:${{ github.ref_name }}-latest-unvalidated-ubuntu"
             "${{ env.CONTAINER_REGISTRY }}/${{ steps.build_variables.outputs.REPO }}:${{ steps.build_variables.outputs.VERSION }}-unvalidated-ubuntu"
+      - name: Build and publish slim JRE 11 container image
+        # Only run this on repositories in the 'spinnaker' org, not on forks.
+        if: startsWith(github.repository, 'spinnaker/')
+        uses: docker/build-push-action@v5
+        with:
+          context: .
+          file: Dockerfile.java11.slim
+          platforms: linux/amd64,linux/arm64
+          push: true
+          tags: |
+            "${{ env.CONTAINER_REGISTRY }}/${{ steps.build_variables.outputs.REPO }}:${{ github.ref_name }}-latest-java11-unvalidated"
+            "${{ env.CONTAINER_REGISTRY }}/${{ steps.build_variables.outputs.REPO }}:${{ steps.build_variables.outputs.VERSION }}-java11-unvalidated"
+            "${{ env.CONTAINER_REGISTRY }}/${{ steps.build_variables.outputs.REPO }}:${{ github.ref_name }}-latest-java11-unvalidated-slim"
+            "${{ env.CONTAINER_REGISTRY }}/${{ steps.build_variables.outputs.REPO }}:${{ steps.build_variables.outputs.VERSION }}-java11-unvalidated-slim"
+      - name: Build and publish ubuntu JRE 11 container image
+        # Only run this on repositories in the 'spinnaker' org, not on forks.
+        if: startsWith(github.repository, 'spinnaker/')
+        uses: docker/build-push-action@v5
+        with:
+          context: .
+          file: Dockerfile.java11.ubuntu
+          push: true
+          tags: |
+            "${{ env.CONTAINER_REGISTRY }}/${{ steps.build_variables.outputs.REPO }}:${{ github.ref_name }}-latest-java11-unvalidated-ubuntu"
+            "${{ env.CONTAINER_REGISTRY }}/${{ steps.build_variables.outputs.REPO }}:${{ steps.build_variables.outputs.VERSION }}-java11-unvalidated-ubuntu"
\ No newline at end of file
diff --git a/.github/workflows/pr.yml b/.github/workflows/pr.yml
index b2b22cec3e..05001bac17 100644
--- a/.github/workflows/pr.yml
+++ b/.github/workflows/pr.yml
@@ -19,7 +19,9 @@ jobs:
         uses: docker/setup-buildx-action@v3
       - uses: actions/setup-java@v3
         with:
-          java-version: 11
+          java-version: |
+            17
+            11
           distribution: 'zulu'
           cache: 'gradle'
       - name: Prepare build variables
@@ -51,3 +53,23 @@ jobs:
           tags: |
             "${{ env.CONTAINER_REGISTRY }}/${{ steps.build_variables.outputs.REPO }}:latest-ubuntu"
             "${{ env.CONTAINER_REGISTRY }}/${{ steps.build_variables.outputs.REPO }}:${{ steps.build_variables.outputs.VERSION }}-ubuntu"
+      - name: Build slim JRE 11 container image
+        uses: docker/build-push-action@v5
+        with:
+          context: .
+          file: Dockerfile.java11.slim
+          platforms: linux/amd64,linux/arm64
+          tags: |
+            "${{ env.CONTAINER_REGISTRY }}/${{ steps.build_variables.outputs.REPO }}:latest-java11"
+            "${{ env.CONTAINER_REGISTRY }}/${{ steps.build_variables.outputs.REPO }}:${{ steps.build_variables.outputs.VERSION }}-java11"
+            "${{ env.CONTAINER_REGISTRY }}/${{ steps.build_variables.outputs.REPO }}:latest-java11-slim"
+            "${{ env.CONTAINER_REGISTRY }}/${{ steps.build_variables.outputs.REPO }}:${{ steps.build_variables.outputs.VERSION }}-java11-slim"
+      - name: Build ubuntu JRE 11 container image
+        uses: docker/build-push-action@v5
+        with:
+          context: .
+          file: Dockerfile.java11.ubuntu
+          platforms: linux/amd64,linux/arm64
+          tags: |
+            "${{ env.CONTAINER_REGISTRY }}/${{ steps.build_variables.outputs.REPO }}:latest-java11-ubuntu"
+            "${{ env.CONTAINER_REGISTRY }}/${{ steps.build_variables.outputs.REPO }}:${{ steps.build_variables.outputs.VERSION }}-java11-ubuntu"
\ No newline at end of file
diff --git a/.github/workflows/release.yml b/.github/workflows/release.yml
index f1cdc027a2..348f7ce649 100644
--- a/.github/workflows/release.yml
+++ b/.github/workflows/release.yml
@@ -43,7 +43,9 @@ jobs:
         uses: docker/setup-buildx-action@v3
       - uses: actions/setup-java@v3
         with:
-          java-version: 11
+          java-version: |
+            17
+            11
           distribution: 'zulu'
           cache: 'gradle'
       - name: Assemble release info
@@ -128,6 +130,31 @@ jobs:
           tags: |
             "${{ env.CONTAINER_REGISTRY }}/${{ steps.build_variables.outputs.REPO }}:${{ steps.release_info.outputs.RELEASE_VERSION }}-unvalidated-ubuntu"
             "${{ env.CONTAINER_REGISTRY }}/${{ steps.build_variables.outputs.REPO }}:${{ steps.release_info.outputs.RELEASE_VERSION }}-${{ steps.build_variables.outputs.VERSION }}-unvalidated-ubuntu"
+      - name: Build and publish slim JRE 11 container image
+        # Only run this on repositories in the 'spinnaker' org, not on forks.
+        if: startsWith(github.repository, 'spinnaker/')
+        uses: docker/build-push-action@v5
+        with:
+          context: .
+          file: Dockerfile.java11.slim
+          platforms: linux/amd64,linux/arm64
+          push: true
+          tags: |
+            "${{ env.CONTAINER_REGISTRY }}/${{ steps.build_variables.outputs.REPO }}:${{ steps.release_info.outputs.RELEASE_VERSION }}-java11-unvalidated"
+            "${{ env.CONTAINER_REGISTRY }}/${{ steps.build_variables.outputs.REPO }}:${{ steps.release_info.outputs.RELEASE_VERSION }}-java11-unvalidated-slim"
+            "${{ env.CONTAINER_REGISTRY }}/${{ steps.build_variables.outputs.REPO }}:${{ steps.release_info.outputs.RELEASE_VERSION }}-${{ steps.build_variables.outputs.VERSION }}-java11-unvalidated-slim"
+      - name: Build and publish ubuntu JRE 11 container image
+        # Only run this on repositories in the 'spinnaker' org, not on forks.
+        if: startsWith(github.repository, 'spinnaker/')
+        uses: docker/build-push-action@v5
+        with:
+          context: .
+          file: Dockerfile.java11.ubuntu
+          platforms: linux/amd64,linux/arm64
+          push: true
+          tags: |
+            "${{ env.CONTAINER_REGISTRY }}/${{ steps.build_variables.outputs.REPO }}:${{ steps.release_info.outputs.RELEASE_VERSION }}-java11-unvalidated-ubuntu"
+            "${{ env.CONTAINER_REGISTRY }}/${{ steps.build_variables.outputs.REPO }}:${{ steps.release_info.outputs.RELEASE_VERSION }}-${{ steps.build_variables.outputs.VERSION }}-java11-unvalidated-ubuntu"
       - name: Create release
         if: steps.release_info.outputs.SKIP_RELEASE == 'false'
         uses: softprops/action-gh-release@v1
diff --git a/Dockerfile.java11.slim b/Dockerfile.java11.slim
new file mode 100644
index 0000000000..7a051d9f2e
--- /dev/null
+++ b/Dockerfile.java11.slim
@@ -0,0 +1,9 @@
+FROM alpine:3.16
+LABEL maintainer="sig-platform@spinnaker.io"
+RUN apk --no-cache add --update bash openjdk11-jre
+RUN addgroup -S -g 10111 spinnaker
+RUN adduser -S -G spinnaker -u 10111 spinnaker
+COPY orca-web/build/install/orca /opt/orca
+RUN mkdir -p /opt/orca/plugins && chown -R spinnaker:nogroup /opt/orca/plugins
+USER spinnaker
+CMD ["/opt/orca/bin/orca"]
diff --git a/Dockerfile.java11.ubuntu b/Dockerfile.java11.ubuntu
new file mode 100644
index 0000000000..16dfa49198
--- /dev/null
+++ b/Dockerfile.java11.ubuntu
@@ -0,0 +1,8 @@
+FROM ubuntu:bionic
+LABEL maintainer="sig-platform@spinnaker.io"
+RUN apt-get update && apt-get -y install openjdk-11-jre-headless wget
+RUN adduser --system --uid 10111 --group spinnaker
+COPY orca-web/build/install/orca /opt/orca
+RUN mkdir -p /opt/orca/plugins && chown -R spinnaker:nogroup /opt/orca/plugins
+USER spinnaker
+CMD ["/opt/orca/bin/orca"]
diff --git a/Dockerfile.slim b/Dockerfile.slim
index 7a051d9f2e..436123ad6c 100644
--- a/Dockerfile.slim
+++ b/Dockerfile.slim
@@ -1,6 +1,6 @@
 FROM alpine:3.16
 LABEL maintainer="sig-platform@spinnaker.io"
-RUN apk --no-cache add --update bash openjdk11-jre
+RUN apk --no-cache add --update bash openjdk17-jre
 RUN addgroup -S -g 10111 spinnaker
 RUN adduser -S -G spinnaker -u 10111 spinnaker
 COPY orca-web/build/install/orca /opt/orca
diff --git a/Dockerfile.ubuntu b/Dockerfile.ubuntu
index 16dfa49198..9adaa1c143 100644
--- a/Dockerfile.ubuntu
+++ b/Dockerfile.ubuntu
@@ -1,6 +1,6 @@
 FROM ubuntu:bionic
 LABEL maintainer="sig-platform@spinnaker.io"
-RUN apt-get update && apt-get -y install openjdk-11-jre-headless wget
+RUN apt-get update && apt-get -y install openjdk-17-jre-headless wget
 RUN adduser --system --uid 10111 --group spinnaker
 COPY orca-web/build/install/orca /opt/orca
 RUN mkdir -p /opt/orca/plugins && chown -R spinnaker:nogroup /opt/orca/plugins
diff --git a/build.gradle b/build.gradle
index d7f711e90a..05b12f1d16 100644
--- a/build.gradle
+++ b/build.gradle
@@ -27,6 +27,17 @@ allprojects {
 
   group = "io.spinnaker.orca"
 
+  tasks.withType(JavaCompile).configureEach {
+    javaCompiler = javaToolchains.compilerFor {
+      languageVersion = JavaLanguageVersion.of(11)
+    }
+  }
+  tasks.withType(Test).configureEach {
+    javaLauncher = javaToolchains.launcherFor {
+      languageVersion = JavaLanguageVersion.of(17)
+    }
+  }
+
   tasks.withType(JavaExec) {
     if (System.getProperty('DEBUG', 'false') == 'true') {
       jvmArgs '-agentlib:jdwp=transport=dt_socket,server=y,suspend=n,address=8183'
diff --git a/gradle.properties b/gradle.properties
index 41e4a4afa1..ee0aaeacf4 100644
--- a/gradle.properties
+++ b/gradle.properties
@@ -2,6 +2,7 @@ fiatVersion=1.42.0
 korkVersion=7.204.0
 kotlinVersion=1.5.32
 org.gradle.parallel=true
+org.gradle.jvmargs=-Xmx6g
 spinnakerGradleVersion=8.31.0
 targetJava11=true
 
diff --git a/orca-clouddriver/src/main/groovy/com/netflix/spinnaker/orca/kato/tasks/JarDiffsTask.groovy b/orca-clouddriver/src/main/groovy/com/netflix/spinnaker/orca/kato/tasks/JarDiffsTask.groovy
index 952d16cbab..80815766bf 100644
--- a/orca-clouddriver/src/main/groovy/com/netflix/spinnaker/orca/kato/tasks/JarDiffsTask.groovy
+++ b/orca-clouddriver/src/main/groovy/com/netflix/spinnaker/orca/kato/tasks/JarDiffsTask.groovy
@@ -19,6 +19,7 @@ package com.netflix.spinnaker.orca.kato.tasks
 import com.netflix.spinnaker.kork.retrofit.exceptions.SpinnakerRetrofitErrorHandler
 import com.netflix.spinnaker.orca.api.pipeline.models.StageExecution
 import com.netflix.spinnaker.orca.clouddriver.model.Instance.InstanceInfo
+import retrofit.converter.JacksonConverter
 
 import java.util.concurrent.TimeUnit
 import java.util.regex.Matcher
@@ -121,6 +122,7 @@ class JarDiffsTask implements DiffTask {
 
     RestAdapter restAdapter = new RestAdapter.Builder()
       .setEndpoint(address)
+      .setConverter(new JacksonConverter())
       .setClient(new OkClient(okHttpClient))
       .setErrorHandler(SpinnakerRetrofitErrorHandler.getInstance())
       .build()
diff --git a/orca-clouddriver/src/main/groovy/com/netflix/spinnaker/orca/kato/tasks/quip/AbstractQuipTask.groovy b/orca-clouddriver/src/main/groovy/com/netflix/spinnaker/orca/kato/tasks/quip/AbstractQuipTask.groovy
index 1af2fce4a0..a7ea17d467 100644
--- a/orca-clouddriver/src/main/groovy/com/netflix/spinnaker/orca/kato/tasks/quip/AbstractQuipTask.groovy
+++ b/orca-clouddriver/src/main/groovy/com/netflix/spinnaker/orca/kato/tasks/quip/AbstractQuipTask.groovy
@@ -22,6 +22,8 @@ import com.netflix.spinnaker.orca.clouddriver.InstanceService
 import com.squareup.okhttp.OkHttpClient
 import retrofit.RestAdapter
 import retrofit.client.OkClient
+import retrofit.converter.JacksonConverter
+
 import static retrofit.RestAdapter.LogLevel.BASIC
 
 @Deprecated
@@ -29,6 +31,7 @@ abstract class AbstractQuipTask implements Task {
   InstanceService createInstanceService(String address) {
     RestAdapter restAdapter = new RestAdapter.Builder()
       .setEndpoint(address)
+      .setConverter(new JacksonConverter())
       .setClient(new OkClient(new OkHttpClient(retryOnConnectionFailure: false)))
       .setLogLevel(BASIC)
       .setErrorHandler(SpinnakerRetrofitErrorHandler.getInstance())
diff --git a/orca-clouddriver/src/test/groovy/com/netflix/spinnaker/orca/clouddriver/pipeline/providers/aws/DeployCloudFormationStageTest.groovy b/orca-clouddriver/src/test/groovy/com/netflix/spinnaker/orca/clouddriver/pipeline/providers/aws/DeployCloudFormationStageTest.groovy
index 0316d8f178..77368892e2 100644
--- a/orca-clouddriver/src/test/groovy/com/netflix/spinnaker/orca/clouddriver/pipeline/providers/aws/DeployCloudFormationStageTest.groovy
+++ b/orca-clouddriver/src/test/groovy/com/netflix/spinnaker/orca/clouddriver/pipeline/providers/aws/DeployCloudFormationStageTest.groovy
@@ -43,7 +43,7 @@ class DeployCloudFormationStageTest extends Specification {
     cloudFormationStage.taskGraph(stage, builder)
 
     then:
-    builder.graph.size == graphSize
+    builder.graph.size() == graphSize
 
     where:
     isChangeSet | executeChangeSet || graphSize
diff --git a/orca-clouddriver/src/test/groovy/com/netflix/spinnaker/orca/clouddriver/pipeline/servergroup/support/TargetServerGroupResolverSpec.groovy b/orca-clouddriver/src/test/groovy/com/netflix/spinnaker/orca/clouddriver/pipeline/servergroup/support/TargetServerGroupResolverSpec.groovy
index e34a386bba..b6400d3015 100644
--- a/orca-clouddriver/src/test/groovy/com/netflix/spinnaker/orca/clouddriver/pipeline/servergroup/support/TargetServerGroupResolverSpec.groovy
+++ b/orca-clouddriver/src/test/groovy/com/netflix/spinnaker/orca/clouddriver/pipeline/servergroup/support/TargetServerGroupResolverSpec.groovy
@@ -31,6 +31,7 @@ import retrofit.client.Client
 import retrofit.client.Response
 import retrofit.converter.ConversionException
 import retrofit.converter.GsonConverter
+import retrofit.converter.JacksonConverter
 import retrofit.mime.TypedString
 import spock.lang.Specification
 import spock.lang.Subject
@@ -67,6 +68,7 @@ class TargetServerGroupResolverSpec extends Specification {
         new RestAdapter.Builder()
             .setEndpoint("clouddriver")
             .setClient(client)
+            .setConverter(new JacksonConverter())
             .setErrorHandler(spinnakerRetrofitErrorHandler)
             .build()
             .create(OortService.class);
@@ -109,6 +111,7 @@ class TargetServerGroupResolverSpec extends Specification {
         new RestAdapter.Builder()
             .setEndpoint("clouddriver")
             .setClient(client)
+            .setConverter(new JacksonConverter())
             .setErrorHandler(spinnakerRetrofitErrorHandler)
             .build()
             .create(OortService.class);
diff --git a/orca-clouddriver/src/test/groovy/com/netflix/spinnaker/orca/clouddriver/pipeline/servergroup/support/TerminatingInstanceSupportSpec.groovy b/orca-clouddriver/src/test/groovy/com/netflix/spinnaker/orca/clouddriver/pipeline/servergroup/support/TerminatingInstanceSupportSpec.groovy
index 4d98df1431..59c02fe8bd 100644
--- a/orca-clouddriver/src/test/groovy/com/netflix/spinnaker/orca/clouddriver/pipeline/servergroup/support/TerminatingInstanceSupportSpec.groovy
+++ b/orca-clouddriver/src/test/groovy/com/netflix/spinnaker/orca/clouddriver/pipeline/servergroup/support/TerminatingInstanceSupportSpec.groovy
@@ -44,9 +44,9 @@ class TerminatingInstanceSupportSpec extends Specification {
       def results = support.remainingInstances(stage)
 
     then:
-      getTSGCount * cloudDriverService.getTargetServerGroup("creds", "santa-claus", "north-pole") >> [
+      getTSGCount * cloudDriverService.getTargetServerGroup("creds", "santa-claus", "north-pole") >> Optional.of([
           new TargetServerGroup(instances: returnedInstances)
-      ]
+      ])
       results == expected
 
     where:
diff --git a/orca-clouddriver/src/test/groovy/com/netflix/spinnaker/orca/clouddriver/tasks/DetermineHealthProvidersTaskSpec.groovy b/orca-clouddriver/src/test/groovy/com/netflix/spinnaker/orca/clouddriver/tasks/DetermineHealthProvidersTaskSpec.groovy
index 4a66f7fd77..e6b7033f6d 100644
--- a/orca-clouddriver/src/test/groovy/com/netflix/spinnaker/orca/clouddriver/tasks/DetermineHealthProvidersTaskSpec.groovy
+++ b/orca-clouddriver/src/test/groovy/com/netflix/spinnaker/orca/clouddriver/tasks/DetermineHealthProvidersTaskSpec.groovy
@@ -34,7 +34,7 @@ class DetermineHealthProvidersTaskSpec extends Specification {
 
   @Subject
   def task = new DetermineHealthProvidersTask(
-    new Optional<Front50Service>(front50Service),
+    Optional<Front50Service>.of(front50Service),
     [],
     [new AmazonServerGroupCreator(), new GoogleServerGroupCreator(), new DcosServerGroupCreator()]
   )
diff --git a/orca-clouddriver/src/test/groovy/com/netflix/spinnaker/orca/clouddriver/tasks/cluster/ShrinkClusterTaskSpec.groovy b/orca-clouddriver/src/test/groovy/com/netflix/spinnaker/orca/clouddriver/tasks/cluster/ShrinkClusterTaskSpec.groovy
index d827c357da..03c8fbc8ad 100644
--- a/orca-clouddriver/src/test/groovy/com/netflix/spinnaker/orca/clouddriver/tasks/cluster/ShrinkClusterTaskSpec.groovy
+++ b/orca-clouddriver/src/test/groovy/com/netflix/spinnaker/orca/clouddriver/tasks/cluster/ShrinkClusterTaskSpec.groovy
@@ -63,7 +63,7 @@ class ShrinkClusterTaskSpec extends Specification {
     1 * cloudDriverService.maybeCluster('foo', 'test', 'foo-test', 'aws') >> Optional.of(cluster)
 
     (expectedItems ? 1 : 0) * katoService.requestOperations('aws', _) >> { p, ops ->
-      assert ops.size == expected.size()
+      assert ops.size() == expected.size()
       expected.each { expect ->
         assert ops.find { it.destroyServerGroup.serverGroupName == expect.name && it.destroyServerGroup.region == expect.region }
       }
diff --git a/orca-core/src/test/groovy/com/netflix/spinnaker/orca/pipeline/util/ArtifactUtilsSpec.groovy b/orca-core/src/test/groovy/com/netflix/spinnaker/orca/pipeline/util/ArtifactUtilsSpec.groovy
index a3d4e48104..c3308625e2 100644
--- a/orca-core/src/test/groovy/com/netflix/spinnaker/orca/pipeline/util/ArtifactUtilsSpec.groovy
+++ b/orca-core/src/test/groovy/com/netflix/spinnaker/orca/pipeline/util/ArtifactUtilsSpec.groovy
@@ -88,7 +88,7 @@ class ArtifactUtilsSpec extends Specification {
 
     then:
     def artifacts = artifactUtils.getArtifacts(desired)
-    artifacts.size == 3
+    artifacts.size() == 3
     artifacts.find { it.type == "1" } != null
     artifacts.find { it.type == "2" } != null
     artifacts.find { it.type == "extra" } != null
@@ -122,7 +122,7 @@ class ArtifactUtilsSpec extends Specification {
 
     then:
     def artifacts = artifactUtils.getArtifacts(desired)
-    artifacts.size == 1
+    artifacts.size() == 1
     artifacts.find { it.type == "1" } != null
 
     where:
@@ -168,7 +168,7 @@ class ArtifactUtilsSpec extends Specification {
 
     then:
     def artifacts = artifactUtils.getArtifacts(desired)
-    artifacts.size == 2
+    artifacts.size() == 2
     artifacts.find { it.type == "1" } != null
     artifacts.find { it.type == "trigger" } != null
   }
@@ -192,7 +192,7 @@ class ArtifactUtilsSpec extends Specification {
 
     then:
     def artifacts = artifactUtils.getArtifacts(desired)
-    artifacts.size == 0
+    artifacts.size() == 0
   }
 
   def "should find a bound artifact from upstream stages"() {
@@ -281,7 +281,7 @@ class ArtifactUtilsSpec extends Specification {
 
     then:
     def artifacts = artifactUtils.getAllArtifacts(execution)
-    artifacts.size == 3
+    artifacts.size() == 3
     artifacts*.type == ["2", "1", "trigger"]
   }
 
@@ -324,7 +324,7 @@ class ArtifactUtilsSpec extends Specification {
 
     then:
     def artifacts = artifactUtils.getArtifactsForPipelineId(pipelineId, executionCriteria)
-    artifacts.size == 3
+    artifacts.size() == 3
     artifacts*.type == ["2", "1", "trigger"]
 
     def emptyArtifacts = artifactUtils.getArtifactsForPipelineId(pipelineId, executionTerminalCriteria)
@@ -362,7 +362,7 @@ class ArtifactUtilsSpec extends Specification {
 
     then:
     def artifacts = artifactUtils.getArtifactsForPipelineIdWithoutStageRef(pipelineId, "2", expectedExecutionCriteria)
-    artifacts.size == 2
+    artifacts.size() == 2
     artifacts*.type == ["1", "trigger"]
   }
 
diff --git a/orca-core/src/test/groovy/com/netflix/spinnaker/orca/pipeline/util/ContextParameterProcessorSpec.groovy b/orca-core/src/test/groovy/com/netflix/spinnaker/orca/pipeline/util/ContextParameterProcessorSpec.groovy
index d11d8f4d4d..d3476ac989 100644
--- a/orca-core/src/test/groovy/com/netflix/spinnaker/orca/pipeline/util/ContextParameterProcessorSpec.groovy
+++ b/orca-core/src/test/groovy/com/netflix/spinnaker/orca/pipeline/util/ContextParameterProcessorSpec.groovy
@@ -452,7 +452,7 @@ class ContextParameterProcessorSpec extends Specification {
     def result = contextParameterProcessor.process(source, contextParameterProcessor.buildExecutionContext(execution), true)
 
     then:
-    result.deployed.size == 2
+    result.deployed.size() == 2
     result.deployed.serverGroup == ["flex-test-v043", "flex-prestaging-v011"]
     result.deployed.region == ["us-east-1", "us-west-1"]
     result.deployed.ami == ["ami-06362b6e", "ami-f759b7b3"]
@@ -601,7 +601,7 @@ class ContextParameterProcessorSpec extends Specification {
     def result = contextParameterProcessor.process(source, contextParameterProcessor.buildExecutionContext(execution), true)
 
     then:
-    result.deployed.size == 2
+    result.deployed.size() == 2
     result.deployed.serverGroup == ["flex-test-v043", "flex-prestaging-v011"]
     result.deployed.region == ["us-east-1", "us-west-1"]
     result.deployed.ami == ["ami-06362b6e", "ami-f759b7b3"]
@@ -612,7 +612,7 @@ class ContextParameterProcessorSpec extends Specification {
     result = contextParameterProcessor.process(source, contextParameterProcessor.buildExecutionContext(execution), true)
 
     then: 'should only consider the specified stage name/id'
-    result.deployed.size == 1
+    result.deployed.size() == 1
     result.deployed.serverGroup == ["flex-test-v043"]
     result.deployed.region == ["us-east-1"]
     result.deployed.ami == ["ami-06362b6e"]
diff --git a/orca-front50/src/test/groovy/com/netflix/spinnaker/orca/front50/tasks/MonitorPipelineTaskSpec.groovy b/orca-front50/src/test/groovy/com/netflix/spinnaker/orca/front50/tasks/MonitorPipelineTaskSpec.groovy
index d46d619327..957495ce1b 100644
--- a/orca-front50/src/test/groovy/com/netflix/spinnaker/orca/front50/tasks/MonitorPipelineTaskSpec.groovy
+++ b/orca-front50/src/test/groovy/com/netflix/spinnaker/orca/front50/tasks/MonitorPipelineTaskSpec.groovy
@@ -104,7 +104,7 @@ class MonitorPipelineTaskSpec extends Specification {
 
     then:
     result.outputs.containsKey("artifacts")
-    result.outputs["artifacts"].size == 1
+    result.outputs["artifacts"].size() == 1
   }
 
   def "propagates pipeline exceptions"() {
diff --git a/orca-igor/src/test/groovy/com/netflix/spinnaker/orca/igor/tasks/GetCommitsTaskSpec.groovy b/orca-igor/src/test/groovy/com/netflix/spinnaker/orca/igor/tasks/GetCommitsTaskSpec.groovy
index 234c727038..ff13049e64 100644
--- a/orca-igor/src/test/groovy/com/netflix/spinnaker/orca/igor/tasks/GetCommitsTaskSpec.groovy
+++ b/orca-igor/src/test/groovy/com/netflix/spinnaker/orca/igor/tasks/GetCommitsTaskSpec.groovy
@@ -211,7 +211,7 @@ class GetCommitsTaskSpec extends Specification {
 
   boolean assertResults(TaskResult result, ExecutionStatus taskStatus) {
     assert result.status == taskStatus
-    assert result.context.commits.size == 2
+    assert result.context.commits.size() == 2
     assert result.context.commits[0].displayId == "abcdab"
     assert result.context.commits[0].id == "abcdabcdabcdabcd"
     assert result.context.commits[0].authorDisplayName == "Joe Coder"
@@ -421,7 +421,7 @@ class GetCommitsTaskSpec extends Specification {
 
     then:
     result.status == taskStatus
-    result.context.commits.size == 0
+    result.context.commits.size() == 0
 
     where:
     app = "myapp"
@@ -472,7 +472,7 @@ class GetCommitsTaskSpec extends Specification {
 
     then:
     result.status == taskStatus
-    result.context.commits.size == 0
+    result.context.commits.size() == 0
 
     where:
     app = "myapp"
@@ -513,7 +513,7 @@ class GetCommitsTaskSpec extends Specification {
 
     then:
     result.status == SUCCEEDED
-    result.context.commits.size == 0
+    result.context.commits.size() == 0
 
     where:
     app = "myapp"
diff --git a/orca-pipelinetemplate/src/test/groovy/com/netflix/spinnaker/orca/pipelinetemplate/PipelineTemplatePipelinePreprocessorSpec.groovy b/orca-pipelinetemplate/src/test/groovy/com/netflix/spinnaker/orca/pipelinetemplate/PipelineTemplatePipelinePreprocessorSpec.groovy
index c2829df10a..60b229df94 100644
--- a/orca-pipelinetemplate/src/test/groovy/com/netflix/spinnaker/orca/pipelinetemplate/PipelineTemplatePipelinePreprocessorSpec.groovy
+++ b/orca-pipelinetemplate/src/test/groovy/com/netflix/spinnaker/orca/pipelinetemplate/PipelineTemplatePipelinePreprocessorSpec.groovy
@@ -344,7 +344,7 @@ class PipelineTemplatePipelinePreprocessorSpec extends Specification {
     def result = subject.process(template)
 
     then:
-    result.stages.size == 4
+    result.stages.size() == 4
     result.stages*.name.toSet() == ["Wait", "Deploy to cluster-1", "Deploy to cluster-2", "Deploy to cluster-3"].toSet()
   }
 
diff --git a/orca-retrofit/src/test/groovy/com/netflix/spinnaker/orca/retrofit/exceptions/BaseRetrofitExceptionHandlerSpec.groovy b/orca-retrofit/src/test/groovy/com/netflix/spinnaker/orca/retrofit/exceptions/BaseRetrofitExceptionHandlerSpec.groovy
index 934d0bf160..debf6e5b09 100644
--- a/orca-retrofit/src/test/groovy/com/netflix/spinnaker/orca/retrofit/exceptions/BaseRetrofitExceptionHandlerSpec.groovy
+++ b/orca-retrofit/src/test/groovy/com/netflix/spinnaker/orca/retrofit/exceptions/BaseRetrofitExceptionHandlerSpec.groovy
@@ -20,6 +20,7 @@ import retrofit.RestAdapter
 import retrofit.RetrofitError
 import retrofit.client.Client
 import retrofit.client.Response
+import retrofit.converter.JacksonConverter
 import retrofit.mime.TypedString
 import spock.lang.Specification
 import spock.lang.Subject
@@ -60,6 +61,7 @@ class BaseRetrofitExceptionHandlerSpec extends Specification {
     def api = new RestAdapter.Builder()
       .setEndpoint("http://localhost:1337")
       .setClient(client)
+      .setConverter(new JacksonConverter())
       .build()
       .create(DummyRetrofitApi)
 
@@ -85,6 +87,7 @@ class BaseRetrofitExceptionHandlerSpec extends Specification {
     def api = new RestAdapter.Builder()
       .setEndpoint("http://localhost:1337")
       .setClient(client)
+      .setConverter(new JacksonConverter())
       .build()
       .create(DummyRetrofitApi)
 
@@ -114,6 +117,7 @@ class BaseRetrofitExceptionHandlerSpec extends Specification {
     def api = new RestAdapter.Builder()
       .setEndpoint("http://localhost:1337")
       .setClient(client)
+      .setConverter(new JacksonConverter())
       .build()
       .create(DummyRetrofitApi)
 
@@ -142,6 +146,7 @@ class BaseRetrofitExceptionHandlerSpec extends Specification {
     and:
     def api = new RestAdapter.Builder()
       .setEndpoint("http://localhost:1337")
+      .setConverter(new JacksonConverter())
       .setClient(client)
       .build()
       .create(DummyRetrofitApi)
diff --git a/orca-retrofit/src/test/java/com/netflix/spinnaker/orca/retrofit/exceptions/SpinnakerServerExceptionHandlerTest.java b/orca-retrofit/src/test/java/com/netflix/spinnaker/orca/retrofit/exceptions/SpinnakerServerExceptionHandlerTest.java
index dc9a60de78..3d4af3c1df 100644
--- a/orca-retrofit/src/test/java/com/netflix/spinnaker/orca/retrofit/exceptions/SpinnakerServerExceptionHandlerTest.java
+++ b/orca-retrofit/src/test/java/com/netflix/spinnaker/orca/retrofit/exceptions/SpinnakerServerExceptionHandlerTest.java
@@ -43,6 +43,7 @@
 import retrofit.client.Request;
 import retrofit.client.Response;
 import retrofit.converter.GsonConverter;
+import retrofit.converter.JacksonConverter;
 import retrofit.mime.TypedString;
 
 class SpinnakerServerExceptionHandlerTest {
@@ -186,6 +187,7 @@ private static Stream<Arguments> exceptionsForRetryTest() throws Exception {
         new RestAdapter.Builder()
             .setEndpoint(URL)
             .setClient(client)
+            .setConverter(new JacksonConverter())
             .setErrorHandler(SpinnakerRetrofitErrorHandler.getInstance())
             .build()
             .create(DummyRetrofitApi.class);