diff --git a/java/ql/lib/qlpack.yml b/java/ql/lib/qlpack.yml
index d6884627794b..f29904e14c56 100644
--- a/java/ql/lib/qlpack.yml
+++ b/java/ql/lib/qlpack.yml
@@ -23,3 +23,4 @@ dataExtensions:
   - ext/generated/*.model.yml
   - ext/experimental/*.model.yml
 warnOnImplicitThis: true
+compileForOverlayEval: true
diff --git a/java/ql/lib/semmle/code/java/Type.qll b/java/ql/lib/semmle/code/java/Type.qll
index c30dd7012bfb..5f9fb1e95023 100644
--- a/java/ql/lib/semmle/code/java/Type.qll
+++ b/java/ql/lib/semmle/code/java/Type.qll
@@ -424,6 +424,15 @@ class RefType extends Type, Annotatable, Modifiable, @reftype {
    */
   RefType getAStrictAncestor() { result = this.getASupertype().getAnAncestor() }
 
+  /**
+   * Gets a direct or indirect supertype of this type.
+   * This does not include itself, unless this type is part of a cycle
+   * in the type hierarchy.
+   */
+  overlay[caller?]
+  pragma[inline]
+  RefType getAStrictAncestorI() { result = this.getASupertype().getAnAncestor() }
+
   /**
    * Gets the source declaration of a direct supertype of this type, excluding itself.
    *
diff --git a/java/ql/lib/semmle/code/java/security/TempDirLocalInformationDisclosureQuery.qll b/java/ql/lib/semmle/code/java/security/TempDirLocalInformationDisclosureQuery.qll
index 97ae75988b3b..1caadd3f8acd 100644
--- a/java/ql/lib/semmle/code/java/security/TempDirLocalInformationDisclosureQuery.qll
+++ b/java/ql/lib/semmle/code/java/security/TempDirLocalInformationDisclosureQuery.qll
@@ -203,6 +203,7 @@ module TempDirSystemGetPropertyDirectlyToMkdir =
 /**
  * A `MethodCall` against a method that creates a temporary file or directory in a shared temporary directory.
  */
+overlay[local?]
 abstract class MethodCallInsecureFileCreation extends MethodCall {
   /**
    * Gets the type of entity created (e.g. `file`, `directory`, ...).
@@ -218,6 +219,7 @@ abstract class MethodCallInsecureFileCreation extends MethodCall {
 /**
  * An insecure call to `java.io.File.createTempFile`.
  */
+overlay[local?]
 class MethodCallInsecureFileCreateTempFile extends MethodCallInsecureFileCreation {
   MethodCallInsecureFileCreateTempFile() {
     this.getMethod() instanceof MethodFileCreateTempFile and
@@ -246,6 +248,7 @@ class MethodGuavaFilesCreateTempFile extends Method {
 /**
  * A call to the `com.google.common.io.Files.createTempDir` method.
  */
+overlay[local?]
 class MethodCallInsecureGuavaFilesCreateTempFile extends MethodCallInsecureFileCreation {
   MethodCallInsecureGuavaFilesCreateTempFile() {
     this.getMethod() instanceof MethodGuavaFilesCreateTempFile
diff --git a/java/ql/src/Language Abuse/UselessTypeTest.ql b/java/ql/src/Language Abuse/UselessTypeTest.ql
index dc727485bda5..a7a1f170fe38 100644
--- a/java/ql/src/Language Abuse/UselessTypeTest.ql	
+++ b/java/ql/src/Language Abuse/UselessTypeTest.ql	
@@ -18,7 +18,7 @@ from InstanceOfExpr ioe, RefType t, RefType ct
 where
   t = ioe.getExpr().getType() and
   ct = ioe.getCheckedType() and
-  ct = t.getAStrictAncestor()
+  ct = t.getAStrictAncestorI()
 select ioe,
   "There is no need to test whether an instance of $@ is also an instance of $@ - it always is.", t,
   t.getName(), ct, ct.getName()
diff --git a/java/ql/src/Language Abuse/UselessUpcast.ql b/java/ql/src/Language Abuse/UselessUpcast.ql
index ea7c12632ecd..d48e782b2e91 100644
--- a/java/ql/src/Language Abuse/UselessUpcast.ql	
+++ b/java/ql/src/Language Abuse/UselessUpcast.ql	
@@ -65,7 +65,7 @@ where
     src = cse.getExpr().getType() and
     dest = cse.getType()
   ) and
-  dest = src.getAStrictAncestor() and
+  dest = src.getAStrictAncestorI() and
   not usefulUpcast(e)
 select e, "There is no need to upcast from $@ to $@ - the conversion can be done implicitly.", src,
   src.getName(), dest, dest.getName()
diff --git a/java/ql/src/Likely Bugs/Finalization/NullifiedSuperFinalize.ql b/java/ql/src/Likely Bugs/Finalization/NullifiedSuperFinalize.ql
index 19bac66e0281..eeef82bcfae0 100644
--- a/java/ql/src/Likely Bugs/Finalization/NullifiedSuperFinalize.ql	
+++ b/java/ql/src/Likely Bugs/Finalization/NullifiedSuperFinalize.ql	
@@ -17,7 +17,7 @@ from FinalizeMethod m, Class c, FinalizeMethod mSuper, Class cSuper
 where
   m.getDeclaringType() = c and
   mSuper.getDeclaringType() = cSuper and
-  c.getAStrictAncestor() = cSuper and
+  c.getAStrictAncestorI() = cSuper and
   not cSuper instanceof TypeObject and
   not exists(m.getBody().getAChild())
 select m, "Finalize in " + c.getName() + " nullifies finalize in " + cSuper.getName() + "."
diff --git a/java/ql/src/Likely Bugs/Inheritance/NoNonFinalInConstructor.ql b/java/ql/src/Likely Bugs/Inheritance/NoNonFinalInConstructor.ql
index 606daac9c083..6b598a5a5c5f 100644
--- a/java/ql/src/Likely Bugs/Inheritance/NoNonFinalInConstructor.ql	
+++ b/java/ql/src/Likely Bugs/Inheritance/NoNonFinalInConstructor.ql	
@@ -47,13 +47,13 @@ where
   ma = unqualifiedCallToNonAbstractMethod(c, m) and
   // ... there exists an overriding method in a subtype,
   n.overrides+(m) and
-  n.getDeclaringType().getAStrictAncestor() = c.getDeclaringType() and
+  n.getDeclaringType().getAStrictAncestorI() = c.getDeclaringType() and
   // ... the method is in a supertype of c,
   m.getDeclaringType() = c.getDeclaringType().getAnAncestor() and
   // ... `n` reads a non-final field `f`,
   fa = nonFinalFieldRead(n, f) and
   // ... which is declared in a subtype of `c`,
-  f.getDeclaringType().getAStrictAncestor() = c.getDeclaringType() and
+  f.getDeclaringType().getAStrictAncestorI() = c.getDeclaringType() and
   // ... `f` is written only in the subtype constructor, and
   fw = fieldWriteOnlyIn(d, f) and
   // ... the subtype constructor calls (possibly indirectly) the offending super constructor.
diff --git a/java/ql/src/Likely Bugs/Serialization/IncorrectSerialVersionUID.ql b/java/ql/src/Likely Bugs/Serialization/IncorrectSerialVersionUID.ql
index af86d90d690d..ca0b890e988d 100644
--- a/java/ql/src/Likely Bugs/Serialization/IncorrectSerialVersionUID.ql	
+++ b/java/ql/src/Likely Bugs/Serialization/IncorrectSerialVersionUID.ql	
@@ -21,5 +21,5 @@ where
     not f.isStatic() or
     not f.getType().hasName("long")
   ) and
-  f.getDeclaringType().getAStrictAncestor() instanceof TypeSerializable
+  f.getDeclaringType().getAStrictAncestorI() instanceof TypeSerializable
 select f, "'serialVersionUID' should be final, static, and of type long."
diff --git a/java/ql/src/Likely Bugs/Serialization/NonSerializableField.ql b/java/ql/src/Likely Bugs/Serialization/NonSerializableField.ql
index a39e29f6576f..d939777e6e1d 100644
--- a/java/ql/src/Likely Bugs/Serialization/NonSerializableField.ql	
+++ b/java/ql/src/Likely Bugs/Serialization/NonSerializableField.ql	
@@ -78,7 +78,7 @@ predicate exceptions(Class c, Field f) {
     f.isStatic()
     or
     // Classes that implement `Externalizable` completely take over control during serialization.
-    externalizable(c.getAStrictAncestor())
+    externalizable(c.getAStrictAncestorI())
     or
     // Stateless session beans are not normally serialized during their usual life-cycle
     // but are forced by their expected supertype to be serializable.
@@ -93,7 +93,7 @@ predicate exceptions(Class c, Field f) {
 from Class c, Field f, string reason
 where
   c.fromSource() and
-  c.getAStrictAncestor() instanceof TypeSerializable and
+  c.getAStrictAncestorI() instanceof TypeSerializable and
   f.getDeclaringType() = c and
   not exceptions(c, f) and
   reason = nonSerialReason(f.getType())
diff --git a/java/ql/src/Likely Bugs/Statements/PartiallyMaskedCatch.ql b/java/ql/src/Likely Bugs/Statements/PartiallyMaskedCatch.ql
index eb5c2d380c65..15278fcde643 100644
--- a/java/ql/src/Likely Bugs/Statements/PartiallyMaskedCatch.ql	
+++ b/java/ql/src/Likely Bugs/Statements/PartiallyMaskedCatch.ql	
@@ -89,7 +89,7 @@ from TryStmt try, int first, int second, RefType masking, RefType masked, string
 where
   try.getFile().isJavaSourceFile() and
   masking = caughtType(try, first) and
-  masking.getAStrictAncestor() = masked and
+  masking.getAStrictAncestorI() = masked and
   masked = caughtType(try, second) and
   forall(RefType thrownType |
     thrownType = getAThrownExceptionType(try) and
diff --git a/java/ql/src/Performance/InnerClassCouldBeStatic.ql b/java/ql/src/Performance/InnerClassCouldBeStatic.ql
index dfc577282ca5..c215890f705f 100644
--- a/java/ql/src/Performance/InnerClassCouldBeStatic.ql
+++ b/java/ql/src/Performance/InnerClassCouldBeStatic.ql
@@ -22,7 +22,7 @@ pragma[nomagic]
 predicate inherits(Class c, Field f) {
   f = c.getAField()
   or
-  not f.isPrivate() and c.getAStrictAncestor().getAField() = f
+  not f.isPrivate() and c.getAStrictAncestorI().getAField() = f
 }
 
 /**
diff --git a/java/ql/src/Security/CWE/CWE-113/NettyResponseSplitting.ql b/java/ql/src/Security/CWE/CWE-113/NettyResponseSplitting.ql
index fb7a40052f0b..f147e50ddb5c 100644
--- a/java/ql/src/Security/CWE/CWE-113/NettyResponseSplitting.ql
+++ b/java/ql/src/Security/CWE/CWE-113/NettyResponseSplitting.ql
@@ -12,6 +12,8 @@
  *       external/cwe/cwe-093
  *       external/cwe/cwe-113
  */
+overlay[local?]
+module;
 
 import java
 import semmle.code.java.dataflow.FlowSources
diff --git a/java/ql/src/Security/CWE/CWE-833/LockOrderInconsistency.ql b/java/ql/src/Security/CWE/CWE-833/LockOrderInconsistency.ql
index 899218838b9a..bfd2dc4be283 100644
--- a/java/ql/src/Security/CWE/CWE-833/LockOrderInconsistency.ql
+++ b/java/ql/src/Security/CWE/CWE-833/LockOrderInconsistency.ql
@@ -134,7 +134,7 @@ predicate inDifferentBranches(MethodCall ma1, MethodCall ma2) {
 /** The method access `ma` occurs in method `runnable`, which is an implementation of `Runnable.run()`. */
 predicate inRunnable(MethodCall ma, Method runnable) {
   runnable.getName() = "run" and
-  runnable.getDeclaringType().getAStrictAncestor().hasQualifiedName("java.lang", "Runnable") and
+  runnable.getDeclaringType().getAStrictAncestorI().hasQualifiedName("java.lang", "Runnable") and
   ma.getEnclosingCallable() = runnable
 }
 
diff --git a/java/ql/src/Violations of Best Practice/Magic Constants/MagicConstantsString.ql b/java/ql/src/Violations of Best Practice/Magic Constants/MagicConstantsString.ql
index c50057c111e9..7c100202d5f4 100644
--- a/java/ql/src/Violations of Best Practice/Magic Constants/MagicConstantsString.ql	
+++ b/java/ql/src/Violations of Best Practice/Magic Constants/MagicConstantsString.ql	
@@ -52,7 +52,7 @@ predicate trivialContext(Literal e) {
   or
   // Message in an exception.
   exists(ClassInstanceExpr constr |
-    constr.getType().(RefType).getAStrictAncestor().hasName("Exception") and
+    constr.getType().(RefType).getAStrictAncestorI().hasName("Exception") and
     e = constr.getArgument(0)
   )
 }
diff --git a/java/ql/src/Violations of Best Practice/Naming Conventions/ConfusingOverridesNames.ql b/java/ql/src/Violations of Best Practice/Naming Conventions/ConfusingOverridesNames.ql
index 1ef2b8c614d3..52c932a8e768 100644
--- a/java/ql/src/Violations of Best Practice/Naming Conventions/ConfusingOverridesNames.ql	
+++ b/java/ql/src/Violations of Best Practice/Naming Conventions/ConfusingOverridesNames.ql	
@@ -65,7 +65,7 @@ where
   ) and
   not exists(Method mid |
     confusing(m1, mid) and
-    mid.getDeclaringType().getAStrictAncestor() = m2.getDeclaringType()
+    mid.getDeclaringType().getAStrictAncestorI() = m2.getDeclaringType()
   ) and
   not exists(Method notConfusing |
     notConfusing.getDeclaringType() = m1.getDeclaringType() and