diff --git a/javac-plugin/src/main/java/org/moditect/deptective/internal/DeptectiveTreeVisitor.java b/javac-plugin/src/main/java/org/moditect/deptective/internal/DeptectiveTreeVisitor.java
index d9267c2..9e998e7 100644
--- a/javac-plugin/src/main/java/org/moditect/deptective/internal/DeptectiveTreeVisitor.java
+++ b/javac-plugin/src/main/java/org/moditect/deptective/internal/DeptectiveTreeVisitor.java
@@ -22,6 +22,7 @@
 import org.moditect.deptective.internal.model.PackageDependencies;
 
 import com.sun.source.tree.AnnotationTree;
+import com.sun.source.tree.ClassTree;
 import com.sun.source.tree.CompilationUnitTree;
 import com.sun.source.tree.ExpressionTree;
 import com.sun.source.tree.MethodTree;
@@ -72,6 +73,8 @@ public Void visitCompilationUnit(CompilationUnitTree tree, Void p) {
         return super.visitCompilationUnit(tree, p);
     }
 
+
+
     //    @Override
     //    public Void visitImport(ImportTree node, Void p) {
     // TODO: Deal with "on-demand-imports" (com.foo.*)
@@ -86,6 +89,18 @@ public Void visitCompilationUnit(CompilationUnitTree tree, Void p) {
     //        return super.visitImport(node, p);
     //    }
 
+    @Override
+    public Void visitClass(ClassTree node, Void p) {
+        Tree extendsClause = node.getExtendsClause();
+        if (extendsClause != null) {
+            checkPackageAccess(extendsClause, getQualifiedName(extendsClause));
+        }
+
+        node.getImplementsClause().forEach(implementsClause -> checkPackageAccess(implementsClause, getQualifiedName(implementsClause)));
+
+        return super.visitClass(node, p);
+    }
+
     @Override
     public Void visitVariable(VariableTree node, Void p) {
         com.sun.tools.javac.tree.JCTree jcTree = (com.sun.tools.javac.tree.JCTree)node;
@@ -138,8 +153,6 @@ public Void visitNewClass(NewClassTree node, Void p) {
         return super.visitNewClass(node, p);
     }
 
-
-
     @Override
     public Void visitMethod(MethodTree node, Void p) {
         Tree returnType = node.getReturnType();
diff --git a/javac-plugin/src/test/java/org/moditect/deptective/plugintest/basic/BasicPluginTest.java b/javac-plugin/src/test/java/org/moditect/deptective/plugintest/basic/BasicPluginTest.java
index 4445c86..07fbd40 100644
--- a/javac-plugin/src/test/java/org/moditect/deptective/plugintest/basic/BasicPluginTest.java
+++ b/javac-plugin/src/test/java/org/moditect/deptective/plugintest/basic/BasicPluginTest.java
@@ -50,6 +50,32 @@ private Compilation compile() {
         return compilation;
     }
 
+    @Test
+    public void shouldDetectInvalidSuperClass() {
+        Compilation compilation = compile();
+        assertThat(compilation).failed();
+
+        assertThat(compilation).hadErrorContaining(
+                "package org.moditect.deptective.plugintest.basic.foo does not read org.moditect.deptective.plugintest.basic.barsuper");
+
+        // inner class
+        assertThat(compilation).hadErrorContaining(
+                "package org.moditect.deptective.plugintest.basic.foo does not read org.moditect.deptective.plugintest.basic.barinnersuper");
+    }
+
+    @Test
+    public void shouldDetectInvalidImplementedInterface() {
+        Compilation compilation = compile();
+        assertThat(compilation).failed();
+
+        assertThat(compilation).hadErrorContaining(
+                "package org.moditect.deptective.plugintest.basic.foo does not read org.moditect.deptective.plugintest.basic.barinter");
+
+        // inner interface
+        assertThat(compilation).hadErrorContaining("package org.moditect.deptective.plugintest.basic.foo does not read org.moditect.deptective.plugintest.basic.barinnerinner");
+    }
+
+
     @Test
     public void shouldDetectInvalidConstructorParameters() {
         Compilation compilation = compile();
diff --git a/javac-plugin/src/test/java/org/moditect/deptective/plugintest/basic/barinnerinner/BarInnerInterface.java b/javac-plugin/src/test/java/org/moditect/deptective/plugintest/basic/barinnerinner/BarInnerInterface.java
new file mode 100644
index 0000000..c3fcad4
--- /dev/null
+++ b/javac-plugin/src/test/java/org/moditect/deptective/plugintest/basic/barinnerinner/BarInnerInterface.java
@@ -0,0 +1,5 @@
+package org.moditect.deptective.plugintest.basic.barinnerinner;
+
+public interface BarInnerInterface {
+
+}
diff --git a/javac-plugin/src/test/java/org/moditect/deptective/plugintest/basic/barinnersuper/BarInnerSuperClass.java b/javac-plugin/src/test/java/org/moditect/deptective/plugintest/basic/barinnersuper/BarInnerSuperClass.java
new file mode 100644
index 0000000..220a7f7
--- /dev/null
+++ b/javac-plugin/src/test/java/org/moditect/deptective/plugintest/basic/barinnersuper/BarInnerSuperClass.java
@@ -0,0 +1,5 @@
+package org.moditect.deptective.plugintest.basic.barinnersuper;
+
+public class BarInnerSuperClass {
+
+}
diff --git a/javac-plugin/src/test/java/org/moditect/deptective/plugintest/basic/barinter/BarInterface.java b/javac-plugin/src/test/java/org/moditect/deptective/plugintest/basic/barinter/BarInterface.java
new file mode 100644
index 0000000..08cf8e8
--- /dev/null
+++ b/javac-plugin/src/test/java/org/moditect/deptective/plugintest/basic/barinter/BarInterface.java
@@ -0,0 +1,5 @@
+package org.moditect.deptective.plugintest.basic.barinter;
+
+public interface BarInterface {
+
+}
diff --git a/javac-plugin/src/test/java/org/moditect/deptective/plugintest/basic/barsuper/BarSuper.java b/javac-plugin/src/test/java/org/moditect/deptective/plugintest/basic/barsuper/BarSuper.java
new file mode 100644
index 0000000..5896559
--- /dev/null
+++ b/javac-plugin/src/test/java/org/moditect/deptective/plugintest/basic/barsuper/BarSuper.java
@@ -0,0 +1,5 @@
+package org.moditect.deptective.plugintest.basic.barsuper;
+
+public class BarSuper {
+
+}
diff --git a/javac-plugin/src/test/java/org/moditect/deptective/plugintest/basic/foo/Foo.java b/javac-plugin/src/test/java/org/moditect/deptective/plugintest/basic/foo/Foo.java
index 6c727ac..60c4ed6 100644
--- a/javac-plugin/src/test/java/org/moditect/deptective/plugintest/basic/foo/Foo.java
+++ b/javac-plugin/src/test/java/org/moditect/deptective/plugintest/basic/foo/Foo.java
@@ -25,16 +25,20 @@
 import org.moditect.deptective.plugintest.basic.barfieldan.BarFieldAnnotation;
 import org.moditect.deptective.plugintest.basic.bargen.BarGeneric;
 import org.moditect.deptective.plugintest.basic.bargentype.BarGenType;
+import org.moditect.deptective.plugintest.basic.barinnerinner.BarInnerInterface;
+import org.moditect.deptective.plugintest.basic.barinnersuper.BarInnerSuperClass;
+import org.moditect.deptective.plugintest.basic.barinter.BarInterface;
 import org.moditect.deptective.plugintest.basic.barlocalvar.BarLocalVar;
 import org.moditect.deptective.plugintest.basic.barloopvar.BarLoopVar;
 import org.moditect.deptective.plugintest.basic.barparameter.BarParameter;
 import org.moditect.deptective.plugintest.basic.barretval.BarRetVal;
 import org.moditect.deptective.plugintest.basic.barretvalgen.RetValGen;
+import org.moditect.deptective.plugintest.basic.barsuper.BarSuper;
 import org.moditect.deptective.plugintest.basic.bartypearg.BarTypeArg;
 
 @FooAnnotation
 @BarClazzAnnotation
-public class Foo {
+public class Foo extends BarSuper implements BarInterface, /* allowed: */ IFoo {
 
 	@BarFieldAnnotation
     private String s;
@@ -65,4 +69,12 @@ private void isAlsoAllowed() { }
     static class InvalidFooGeneric<T extends BarGeneric> {}
 
     static class InvalidFooImplementation extends FooContainer<BarGenType> {}
+
+    static interface InnerFoo extends BarInnerInterface {
+
+    }
+
+    static class InnerFooClass extends BarInnerSuperClass {
+
+    }
 }
diff --git a/javac-plugin/src/test/java/org/moditect/deptective/plugintest/basic/foo/IFoo.java b/javac-plugin/src/test/java/org/moditect/deptective/plugintest/basic/foo/IFoo.java
new file mode 100644
index 0000000..0dfa45f
--- /dev/null
+++ b/javac-plugin/src/test/java/org/moditect/deptective/plugintest/basic/foo/IFoo.java
@@ -0,0 +1,5 @@
+package org.moditect.deptective.plugintest.basic.foo;
+
+public interface IFoo {
+
+}