--- old/src/jdk.internal.vm.compiler/share/classes/org.graalvm.compiler.replacements.test/src/org/graalvm/compiler/replacements/test/RootMethodSubstitutionTest.java	2019-05-16 21:17:51.916259198 +0200
+++ new/src/jdk.internal.vm.compiler/share/classes/org.graalvm.compiler.replacements.test/src/org/graalvm/compiler/replacements/test/RootMethodSubstitutionTest.java	2019-05-16 21:17:51.508256563 +0200
@@ -35,6 +35,7 @@
 import org.graalvm.compiler.core.test.GraalCompilerTest;
 import org.graalvm.compiler.debug.DebugContext;
 import org.graalvm.compiler.nodes.StructuredGraph;
+import org.graalvm.compiler.nodes.graphbuilderconf.InvocationPlugin;
 import org.graalvm.compiler.nodes.graphbuilderconf.InvocationPlugins;
 import org.graalvm.compiler.nodes.graphbuilderconf.MethodSubstitutionPlugin;
 import org.graalvm.compiler.options.OptionValues;
@@ -95,7 +96,11 @@
                         }
                     }
                     if (!original.isNative()) {
-                        ret.add(new Object[]{original});
+                        // Make sure the plugin we found hasn't been overridden.
+                        InvocationPlugin plugin = providers.getReplacements().getGraphBuilderPlugins().getInvocationPlugins().lookupInvocation(original);
+                        if (plugin instanceof MethodSubstitutionPlugin) {
+                            ret.add(new Object[]{original});
+                        }
                     }
                 }
             }