diff --git a/firebase-crashlytics/src/main/java/com/google/firebase/crashlytics/internal/common/CrashlyticsCore.java b/firebase-crashlytics/src/main/java/com/google/firebase/crashlytics/internal/common/CrashlyticsCore.java
index 494802ae676..073b621fb70 100644
--- a/firebase-crashlytics/src/main/java/com/google/firebase/crashlytics/internal/common/CrashlyticsCore.java
+++ b/firebase-crashlytics/src/main/java/com/google/firebase/crashlytics/internal/common/CrashlyticsCore.java
@@ -22,6 +22,7 @@
 import androidx.annotation.VisibleForTesting;
 import com.google.android.gms.tasks.Task;
 import com.google.android.gms.tasks.Tasks;
+import com.google.errorprone.annotations.CanIgnoreReturnValue;
 import com.google.firebase.FirebaseApp;
 import com.google.firebase.crashlytics.BuildConfig;
 import com.google.firebase.crashlytics.internal.CrashlyticsNativeComponent;
@@ -220,6 +221,7 @@ public boolean onPreExecute(AppData appData, SettingsProvider settingsProvider)
   }
 
   /** Performs background initialization asynchronously on the background worker's thread. */
+  @CanIgnoreReturnValue
   public Task<Void> doBackgroundInitializationAsync(SettingsProvider settingsProvider) {
     return Utils.callTask(
         crashHandlerExecutor,
@@ -232,6 +234,7 @@ public Task<Void> call() throws Exception {
   }
 
   /** Performs background initialization synchronously on the calling thread. */
+  @CanIgnoreReturnValue
   private Task<Void> doBackgroundInitialization(SettingsProvider settingsProvider) {
     // create the marker for this run
     markInitializationStarted();
diff --git a/firebase-crashlytics/src/main/java/com/google/firebase/crashlytics/internal/common/CrashlyticsReportDataCapture.java b/firebase-crashlytics/src/main/java/com/google/firebase/crashlytics/internal/common/CrashlyticsReportDataCapture.java
index b8ad6c967de..9f79ebf7041 100644
--- a/firebase-crashlytics/src/main/java/com/google/firebase/crashlytics/internal/common/CrashlyticsReportDataCapture.java
+++ b/firebase-crashlytics/src/main/java/com/google/firebase/crashlytics/internal/common/CrashlyticsReportDataCapture.java
@@ -46,6 +46,7 @@
  * This class is responsible for capturing information from the system and exception objects,
  * parsing them, and returning canonical CrashlyticsReport and Event objects.
  */
+@SuppressWarnings("KotlinInternal")
 public class CrashlyticsReportDataCapture {
 
   private static final Map<String, Integer> ARCHITECTURES_BY_NAME = new HashMap<>();
diff --git a/firebase-crashlytics/src/main/java/com/google/firebase/crashlytics/internal/common/Utils.java b/firebase-crashlytics/src/main/java/com/google/firebase/crashlytics/internal/common/Utils.java
index 61f376a6f38..645c3fb3d95 100644
--- a/firebase-crashlytics/src/main/java/com/google/firebase/crashlytics/internal/common/Utils.java
+++ b/firebase-crashlytics/src/main/java/com/google/firebase/crashlytics/internal/common/Utils.java
@@ -19,6 +19,8 @@
 import com.google.android.gms.tasks.Continuation;
 import com.google.android.gms.tasks.Task;
 import com.google.android.gms.tasks.TaskCompletionSource;
+import com.google.errorprone.annotations.CanIgnoreReturnValue;
+
 import java.util.concurrent.Callable;
 import java.util.concurrent.CancellationException;
 import java.util.concurrent.CountDownLatch;
@@ -135,6 +137,7 @@ public static <T> T awaitEvenIfOnMainThread(Task<T> task)
   }
 
   /** Invokes latch.await(timeout, unit) uninterruptibly. */
+  @CanIgnoreReturnValue
   public static boolean awaitUninterruptibly(CountDownLatch latch, long timeout, TimeUnit unit) {
     boolean interrupted = false;
     try {
diff --git a/firebase-crashlytics/src/main/java/com/google/firebase/crashlytics/internal/metadata/RolloutAssignmentList.java b/firebase-crashlytics/src/main/java/com/google/firebase/crashlytics/internal/metadata/RolloutAssignmentList.java
index 06b38c8001c..761ba1ca57f 100644
--- a/firebase-crashlytics/src/main/java/com/google/firebase/crashlytics/internal/metadata/RolloutAssignmentList.java
+++ b/firebase-crashlytics/src/main/java/com/google/firebase/crashlytics/internal/metadata/RolloutAssignmentList.java
@@ -14,6 +14,7 @@
 
 package com.google.firebase.crashlytics.internal.metadata;
 
+import com.google.errorprone.annotations.CanIgnoreReturnValue;
 import com.google.firebase.crashlytics.internal.Logger;
 import com.google.firebase.crashlytics.internal.model.CrashlyticsReport;
 import java.util.ArrayList;
@@ -38,6 +39,7 @@ public synchronized List<RolloutAssignment> getRolloutAssignmentList() {
     return Collections.unmodifiableList(new ArrayList<RolloutAssignment>(rolloutsState));
   }
 
+  @CanIgnoreReturnValue
   public synchronized boolean updateRolloutAssignmentList(List<RolloutAssignment> newMapList) {
     rolloutsState.clear();
     int nOverLimit = 0;
diff --git a/firebase-crashlytics/src/main/java/com/google/firebase/crashlytics/internal/metadata/UserMetadata.java b/firebase-crashlytics/src/main/java/com/google/firebase/crashlytics/internal/metadata/UserMetadata.java
index 645ad0670a4..bff27633526 100644
--- a/firebase-crashlytics/src/main/java/com/google/firebase/crashlytics/internal/metadata/UserMetadata.java
+++ b/firebase-crashlytics/src/main/java/com/google/firebase/crashlytics/internal/metadata/UserMetadata.java
@@ -16,6 +16,8 @@
 
 import androidx.annotation.Nullable;
 import androidx.annotation.VisibleForTesting;
+
+import com.google.errorprone.annotations.CanIgnoreReturnValue;
 import com.google.firebase.crashlytics.internal.common.CommonUtils;
 import com.google.firebase.crashlytics.internal.common.CrashlyticsBackgroundWorker;
 import com.google.firebase.crashlytics.internal.model.CrashlyticsReport;
@@ -180,6 +182,7 @@ public List<CrashlyticsReport.Session.Event.RolloutAssignment> getRolloutsState(
    * Update RolloutsState in memory and persistence. Return True if update successfully, false
    * otherwise
    */
+  @CanIgnoreReturnValue
   public boolean updateRolloutsState(List<RolloutAssignment> rolloutAssignments) {
     synchronized (rolloutsState) {
       if (!rolloutsState.updateRolloutAssignmentList(rolloutAssignments)) {
diff --git a/firebase-crashlytics/src/main/java/com/google/firebase/crashlytics/internal/model/CrashlyticsReport.java b/firebase-crashlytics/src/main/java/com/google/firebase/crashlytics/internal/model/CrashlyticsReport.java
index bdb98f752b0..63ab0b4e712 100644
--- a/firebase-crashlytics/src/main/java/com/google/firebase/crashlytics/internal/model/CrashlyticsReport.java
+++ b/firebase-crashlytics/src/main/java/com/google/firebase/crashlytics/internal/model/CrashlyticsReport.java
@@ -1119,7 +1119,7 @@ public static RolloutsState.Builder builder() {
         public abstract static class Builder {
           @NonNull
           public abstract RolloutsState.Builder setRolloutAssignments(
-              @Nullable List<RolloutAssignment> rolloutAssignments);
+              @NonNull List<RolloutAssignment> rolloutAssignments);
 
           @NonNull
           public abstract RolloutsState build();
@@ -1215,7 +1215,7 @@ public abstract static class Builder {
         @NonNull
         public abstract Builder setLog(@NonNull Log value);
 
-        @Nullable
+        @NonNull
         public abstract Builder setRollouts(@NonNull RolloutsState rolloutsState);
 
         @NonNull