diff --git a/pitest-entry/src/main/java/org/pitest/mutationtest/build/intercept/javafeatures/ImplicitNullCheckFilter.java b/pitest-entry/src/main/java/org/pitest/mutationtest/build/intercept/javafeatures/ImplicitNullCheckFilter.java
index bcd4fb0c2..da8974ab1 100644
--- a/pitest-entry/src/main/java/org/pitest/mutationtest/build/intercept/javafeatures/ImplicitNullCheckFilter.java
+++ b/pitest-entry/src/main/java/org/pitest/mutationtest/build/intercept/javafeatures/ImplicitNullCheckFilter.java
@@ -12,7 +12,6 @@
 
 import org.objectweb.asm.tree.AbstractInsnNode;
 import org.objectweb.asm.tree.LabelNode;
-import org.objectweb.asm.tree.MethodInsnNode;
 import org.pitest.bytecode.analysis.ClassTree;
 import org.pitest.bytecode.analysis.MethodTree;
 import org.pitest.classinfo.ClassName;
@@ -23,6 +22,7 @@
 import org.pitest.mutationtest.engine.Mutater;
 import org.pitest.mutationtest.engine.MutationDetails;
 import org.pitest.sequence.Context;
+import org.pitest.sequence.Match;
 import org.pitest.sequence.QueryParams;
 import org.pitest.sequence.QueryStart;
 import org.pitest.sequence.SequenceMatcher;
@@ -36,7 +36,7 @@ public class ImplicitNullCheckFilter implements MutationInterceptor {
 
   static final SequenceMatcher<AbstractInsnNode> GET_CLASS_NULL_CHECK = QueryStart
       .any(AbstractInsnNode.class)
-      .then(methodCallTo(ClassName.fromClass(Object.class), "getClass").and(isInstruction(MUTATED_INSTRUCTION.read())))
+      .then(aGetClassCall().and(isInstruction(MUTATED_INSTRUCTION.read())))
       .then(POP) // immediate discard
       .then(isA(LabelNode.class).negate()) // use presence of a label to indicate this was a programmer call to getClass
       .zeroOrMore(QueryStart.match(anyInstruction()))
@@ -45,6 +45,10 @@ public class ImplicitNullCheckFilter implements MutationInterceptor {
           .withDebug(DEBUG)
           );
 
+  private static Match<AbstractInsnNode> aGetClassCall() {
+    return methodCallTo(ClassName.fromClass(Object.class), "getClass");
+  }
+
 
   private ClassTree currentClass;
 
@@ -73,10 +77,11 @@ private Predicate<MutationDetails> isAnImplicitNullCheck() {
       final AbstractInsnNode mutatedInstruction = method.instruction(instruction);
 
       // performance hack
-      if (!(mutatedInstruction instanceof MethodInsnNode)) {
-        return false;
+      if (!aGetClassCall().asPredicate().test(mutatedInstruction)) {
+          return false;
       }
 
+
       Context context = Context.start(DEBUG);
       context = context.store(MUTATED_INSTRUCTION.write(), mutatedInstruction);
       return GET_CLASS_NULL_CHECK.matches(method.instructions(), context);