 diff --git a/src/com/google/javascript/jscomp/AmbiguateProperties.java b/src/com/google/javascript/jscomp/AmbiguateProperties.java
-index 14fe1c32..e15cf15b 100644
+index 14fe1c32..aad743ff 100644
 --- a/src/com/google/javascript/jscomp/AmbiguateProperties.java
 +++ b/src/com/google/javascript/jscomp/AmbiguateProperties.java
 @@ -207,6 +207,7 @@ class AmbiguateProperties implements CompilerPass {

         propsByFreq.add(p);
       } else {
         ++numSkippedPropertyNames;
@@ -247,16 +248,8 @@ class AmbiguateProperties implements CompilerPass {
                 + numSkippedPropertyNames + " properties.");
   }
 
-  private BitSet getRelatedTypesOnNonUnion(JSType type) {
     // All of the types we encounter should have been added to the
     // relatedBitsets via computeRelatedTypes.
-    if (relatedBitsets.containsKey(type)) {
-      return relatedBitsets.get(type);
-    } else {
-      throw new RuntimeException("Related types should have been computed for"
-                                 + " type: " + type + " but have not been.");
-    }
-  }
 
   /** Add supertypes of the type to its JSTypeBitSet of related types. */
   private void computeRelatedTypes(JSType type) {
@@ -352,7 +345,7 @@ class AmbiguateProperties implements CompilerPass {
       if (typesRelatedToSet.intersects(prop.typesSet)) {
         return false;
       }

     }
 
     /**
@@ -362,7 +363,7 @@ class AmbiguateProperties implements CompilerPass {
      */
     public void addNode(Property prop) {
       typesInSet.or(prop.typesSet);
