diff --git a/src/com/google/javascript/jscomp/RemoveUnusedPolyfills.java b/src/com/google/javascript/jscomp/RemoveUnusedPolyfills.java
index 36343be2cc6..63f818acfce 100644
--- a/src/com/google/javascript/jscomp/RemoveUnusedPolyfills.java
+++ b/src/com/google/javascript/jscomp/RemoveUnusedPolyfills.java
@@ -23,8 +23,8 @@
 import com.google.common.collect.SetMultimap;
 import com.google.javascript.jscomp.NodeTraversal.AbstractPostOrderCallback;
 import com.google.javascript.rhino.Node;
+import com.google.javascript.rhino.TypeI;
 import com.google.javascript.rhino.TypeIRegistry;
-import com.google.javascript.rhino.jstype.JSType;
 import com.google.javascript.rhino.jstype.JSTypeNative;
 import java.util.HashMap;
 import java.util.Map;
@@ -132,7 +132,13 @@ void visitPossiblePolyfillUse(Node n) {
       if (methods.isEmpty()) {
         return;
       }
-      JSType receiverType = n.getFirstChild().getJSType();
+      TypeI receiverType = n.getFirstChild().getTypeI();
+      if (NodeUtil.isPrototypeProperty(n)) {
+        TypeI maybeCtor = n.getFirstFirstChild().getTypeI();
+        if (maybeCtor != null && maybeCtor.isConstructor()) {
+          receiverType = maybeCtor.toMaybeFunctionType().getInstanceType();
+        }
+      }
       if (receiverType == null) {
         // TODO(sdh): When does this happen?  If it means incomplete type information, then
         // we need to remove all the potential methods.  If not, we can just return.
@@ -142,8 +148,8 @@ void visitPossiblePolyfillUse(Node n) {
       receiverType = receiverType.restrictByNotNullOrUndefined();
       TypeIRegistry registry = compiler.getTypeIRegistry();
       if (receiverType.isUnknownType()
-          || receiverType.isEmptyType()
-          || receiverType.isAllType()
+          || receiverType.isBottom()
+          || receiverType.isTop()
           || receiverType.isEquivalentTo(
               registry.getNativeType(JSTypeNative.OBJECT_TYPE))) {
         unusedMethodPolyfills.keySet().removeAll(methods);
@@ -158,12 +164,12 @@ void visitPossiblePolyfillUse(Node n) {
     }
 
     private void checkType(
-        JSType targetType, TypeIRegistry registry, PrototypeMethod method, String typeName) {
-      JSType type = registry.getType(typeName);
+        TypeI receiverType, TypeIRegistry registry, PrototypeMethod method, String typeName) {
+      TypeI type = registry.getType(typeName);
       if (type == null) {
         throw new RuntimeException("Missing built-in type: " + typeName);
       }
-      if (!targetType.getGreatestSubtype(type).isBottom()) {
+      if (!receiverType.meetWith(type).isBottom()) {
         unusedMethodPolyfills.remove(method);
       }
     }
diff --git a/src/com/google/javascript/jscomp/newtypes/JSType.java b/src/com/google/javascript/jscomp/newtypes/JSType.java
index 5bb3c57b052..45e0a6df024 100644
--- a/src/com/google/javascript/jscomp/newtypes/JSType.java
+++ b/src/com/google/javascript/jscomp/newtypes/JSType.java
@@ -1625,6 +1625,11 @@ public ObjectTypeI autoboxAndGetObject() {
     return this.autobox().restrictByNotNullOrUndefined().toMaybeObjectType();
   }
 
+  @Override
+  public TypeI meetWith(TypeI other) {
+    return meet(this, (JSType) other);
+  }
+
   @Override
   public boolean equals(Object o) {
     if (o == null) {
diff --git a/src/com/google/javascript/rhino/TypeI.java b/src/com/google/javascript/rhino/TypeI.java
index 57054300690..3f5f0aec472 100644
--- a/src/com/google/javascript/rhino/TypeI.java
+++ b/src/com/google/javascript/rhino/TypeI.java
@@ -118,5 +118,7 @@ public interface TypeI {
    */
   Iterable<? extends TypeI> getUnionMembers();
 
+  TypeI meetWith(TypeI other);
+
   String getDisplayName();
 }
diff --git a/src/com/google/javascript/rhino/jstype/JSType.java b/src/com/google/javascript/rhino/jstype/JSType.java
index 7f371e31b03..98e30edaa4c 100644
--- a/src/com/google/javascript/rhino/jstype/JSType.java
+++ b/src/com/google/javascript/rhino/jstype/JSType.java
@@ -1047,6 +1047,11 @@ public JSType getGreatestSubtype(JSType that) {
     return getGreatestSubtype(this, that);
   }
 
+  @Override
+  public TypeI meetWith(TypeI that) {
+    return getGreatestSubtype(this, (JSType) that);
+  }
+
   /**
    * A generic implementation meant to be used as a helper for common
    * getGreatestSubtype implementations.
diff --git a/test/com/google/javascript/jscomp/RemoveUnusedPolyfillsTest.java b/test/com/google/javascript/jscomp/RemoveUnusedPolyfillsTest.java
index 35a92315470..54b52e0ccee 100644
--- a/test/com/google/javascript/jscomp/RemoveUnusedPolyfillsTest.java
+++ b/test/com/google/javascript/jscomp/RemoveUnusedPolyfillsTest.java
@@ -17,14 +17,14 @@
 package com.google.javascript.jscomp;
 
 /** Unit tests for the RemoveUnusedPolyfills compiler pass. */
-public final class RemoveUnusedPolyfillsTest extends CompilerTestCase {
+public final class RemoveUnusedPolyfillsTest extends TypeICompilerTestCase {
 
   private static final String EXTERNS = LINE_JOINER.join(
+      DEFAULT_EXTERNS,
       // Polyfill
       "var $jscomp = {};",
       "$jscomp.polyfill = function(name, func, from, to) {};",
       // Methods
-      "Function.prototype.call = function(ctx) {};",
       "Array.prototype.includes = function() {};",
       "String.prototype.includes = function() {};",
       "/** @constructor */ function Foo() {}",
@@ -62,7 +62,6 @@ public final class RemoveUnusedPolyfillsTest extends CompilerTestCase {
 
   public RemoveUnusedPolyfillsTest() {
     super(EXTERNS);
-    enableTypeCheck();
   }
 
   @Override
@@ -70,6 +69,14 @@ protected CompilerPass getProcessor(final Compiler compiler) {
     return new RemoveUnusedPolyfills(compiler);
   }
 
+  @Override
+  protected CompilerOptions getOptions() {
+    CompilerOptions options = super.getOptions();
+    // NTI warns about property accesses on *
+    options.setWarningLevel(DiagnosticGroups.NEW_CHECK_TYPES_EXTRA_CHECKS, CheckLevel.OFF);
+    return options;
+  }
+
   public void testRemovesPolyfillInstanceMethods() {
     test(STRING_INCLUDES, "");
     test(STRING_INCLUDES + ARRAY_INCLUDES, "");
@@ -104,6 +111,8 @@ public void testDoesNotRemoveMethodsCalledOnAllType() {
   public void testDoesNotRemoveMethodsCalledOnObject() {
     testSame(STRING_INCLUDES + "obj.includes();");
     testSame(BOTH_INCLUDES + "obj.includes();");
+    testSame(ARRAY_INCLUDES
+        + "function f(/** !Object */ x) { x.includes = function() {}; x.includes(); }");
   }
 
   public void testDoesNotRemoveMethodsCalledOnCorrectTypes() {