diff --git a/src/jdk.compiler/share/classes/com/sun/tools/javac/comp/Attr.java b/src/jdk.compiler/share/classes/com/sun/tools/javac/comp/Attr.java
index 7bd813cddb73a..ae489536ec4fc 100644
--- a/src/jdk.compiler/share/classes/com/sun/tools/javac/comp/Attr.java
+++ b/src/jdk.compiler/share/classes/com/sun/tools/javac/comp/Attr.java
@@ -50,9 +50,11 @@
 import com.sun.tools.javac.comp.DeferredAttr.AttrMode;
 import com.sun.tools.javac.comp.MatchBindingsComputer.MatchBindings;
 import com.sun.tools.javac.jvm.*;
+
 import static com.sun.tools.javac.resources.CompilerProperties.Fragments.Diamond;
 import static com.sun.tools.javac.resources.CompilerProperties.Fragments.DiamondInvalidArg;
 import static com.sun.tools.javac.resources.CompilerProperties.Fragments.DiamondInvalidArgs;
+
 import com.sun.tools.javac.resources.CompilerProperties.Errors;
 import com.sun.tools.javac.resources.CompilerProperties.Fragments;
 import com.sun.tools.javac.resources.CompilerProperties.Warnings;
@@ -2909,6 +2911,12 @@ private void visitAnonymousClassDefinition(JCNewClass tree, JCExpression clazz,
             //       ...
             //     }
             InferenceContext inferenceContext = resultInfo.checkContext.inferenceContext();
+            Type enclType = clazztype.getEnclosingType();
+            if (enclType != null &&
+                    enclType.hasTag(CLASS) &&
+                    !chk.checkDenotable((ClassType)enclType)) {
+                log.error(tree.encl, Errors.EnclosingClassTypeNonDenotable(enclType));
+            }
             final boolean isDiamond = TreeInfo.isDiamond(tree);
             if (isDiamond
                     && ((tree.constructorType != null && inferenceContext.free(tree.constructorType))
diff --git a/src/jdk.compiler/share/classes/com/sun/tools/javac/resources/compiler.properties b/src/jdk.compiler/share/classes/com/sun/tools/javac/resources/compiler.properties
index 3fd713fabfcb1..ae2f1f8c6fc75 100644
--- a/src/jdk.compiler/share/classes/com/sun/tools/javac/resources/compiler.properties
+++ b/src/jdk.compiler/share/classes/com/sun/tools/javac/resources/compiler.properties
@@ -3912,3 +3912,8 @@ compiler.warn.declared.using.preview=\
 
 compiler.warn.attempt.to.synchronize.on.instance.of.value.based.class=\
     attempt to synchronize on an instance of a value-based class
+
+# 0: type
+compiler.err.enclosing.class.type.non.denotable=\
+    enclosing class type: {0}\n\
+    is non-denotable, try casting to a denotable type
diff --git a/test/langtools/tools/javac/8203436/T8203436a.java b/test/langtools/tools/javac/8203436/T8203436a.java
index eba0f827c8626..db47a62e67270 100644
--- a/test/langtools/tools/javac/8203436/T8203436a.java
+++ b/test/langtools/tools/javac/8203436/T8203436a.java
@@ -1,6 +1,6 @@
 /*
  * @test /nodynamiccopyright/
- * @bug 8203436
+ * @bug 8203436 8211004
  * @summary javac should fail early when emitting illegal signature attributes
  * @compile/fail/ref=T8203436a.out -XDrawDiagnostics T8203436a.java
  */
diff --git a/test/langtools/tools/javac/8203436/T8203436a.out b/test/langtools/tools/javac/8203436/T8203436a.out
index 71b7e6871664f..e076a20a2a845 100644
--- a/test/langtools/tools/javac/8203436/T8203436a.out
+++ b/test/langtools/tools/javac/8203436/T8203436a.out
@@ -1,2 +1,2 @@
-- compiler.err.cannot.generate.class: compiler.misc.anonymous.class: T8203436a$1, (compiler.misc.illegal.signature: compiler.misc.anonymous.class: T8203436a$1, compiler.misc.type.captureof: 1, ?)
+T8203436a.java:12:7: compiler.err.enclosing.class.type.non.denotable: T8203436a<compiler.misc.type.captureof: 1, ?>
 1 error
diff --git a/test/langtools/tools/javac/8203436/T8203436b.out b/test/langtools/tools/javac/8203436/T8203436b.out
index 979e550fff6c8..48eb947cecf1e 100644
--- a/test/langtools/tools/javac/8203436/T8203436b.out
+++ b/test/langtools/tools/javac/8203436/T8203436b.out
@@ -1,2 +1,2 @@
-- compiler.err.cannot.generate.class: compiler.misc.anonymous.class: T8203436b$1, (compiler.misc.illegal.signature: compiler.misc.anonymous.class: T8203436b$1, java.lang.Object&T8203436b.A&T8203436b.B)
+T8203436b.java:17:10: compiler.err.enclosing.class.type.non.denotable: T8203436b<java.lang.Object&T8203436b.A&T8203436b.B>
 1 error
diff --git a/test/langtools/tools/javac/diags/examples.not-yet.txt b/test/langtools/tools/javac/diags/examples.not-yet.txt
index f257b7df8e09d..9f9f8f7801447 100644
--- a/test/langtools/tools/javac/diags/examples.not-yet.txt
+++ b/test/langtools/tools/javac/diags/examples.not-yet.txt
@@ -206,3 +206,4 @@ compiler.warn.source.target.conflict
 compiler.warn.target.default.source.conflict
 compiler.err.preview.not.latest
 compiler.err.preview.without.source.or.release
+compiler.misc.illegal.signature                               # the compiler can now detect more non-denotable types before class writing
diff --git a/test/langtools/tools/javac/diags/examples/IllegalSignature.java b/test/langtools/tools/javac/diags/examples/IllegalSignature.java
index a9b64b41afa68..96b93b6bdabbd 100644
--- a/test/langtools/tools/javac/diags/examples/IllegalSignature.java
+++ b/test/langtools/tools/javac/diags/examples/IllegalSignature.java
@@ -21,8 +21,7 @@
  * questions.
  */
 
-// key: compiler.err.cannot.generate.class
-// key: compiler.misc.illegal.signature
+// key: compiler.err.enclosing.class.type.non.denotable
 
 class IllegalSignature<X> {
     class Inner { }
diff --git a/test/langtools/tools/javac/generics/diamond/neg/Neg21.out b/test/langtools/tools/javac/generics/diamond/neg/Neg21.out
index 35e1a94cc156e..d273f7ae71300 100644
--- a/test/langtools/tools/javac/generics/diamond/neg/Neg21.out
+++ b/test/langtools/tools/javac/generics/diamond/neg/Neg21.out
@@ -1,2 +1,3 @@
+Neg21.java:13:9: compiler.err.enclosing.class.type.non.denotable: Neg21<java.lang.Object&java.io.Serializable&java.lang.Cloneable>
 Neg21.java:13:28: compiler.err.cant.apply.diamond.1: (compiler.misc.diamond: Neg21.A), (compiler.misc.diamond.invalid.arg: java.lang.Object&java.io.Serializable&java.lang.Cloneable, (compiler.misc.diamond: Neg21.A))
-1 error
+2 errors