diff --git a/js/src/jsatom.h b/js/src/jsatom.h
index 21f2d6e46004..356493321382 100644
--- a/js/src/jsatom.h
+++ b/js/src/jsatom.h
@@ -115,7 +115,7 @@ struct DefaultHasher<jsid>
     typedef jsid Lookup;
     static HashNumber hash(const Lookup &l) {
         JS_ASSERT(l == js_CheckForStringIndex(l));
-        return JSID_BITS(l);
+        return HashNumber(JSID_BITS(l));
     }
     static bool match(const jsid &id, const Lookup &l) {
         JS_ASSERT(l == js_CheckForStringIndex(l));
diff --git a/js/src/jsobj.h b/js/src/jsobj.h
index 84ba0d8f9e6a..7b881e7a3536 100644
--- a/js/src/jsobj.h
+++ b/js/src/jsobj.h
@@ -594,7 +594,7 @@ struct JSObject : js::gc::Cell {
 
     /* gc::FinalizeKind */ unsigned finalizeKind() const;
 
-    uint32 numSlots() const { return capacity; }
+    uint32 numSlots() const { return uint32(capacity); }
 
     size_t slotsAndStructSize(uint32 nslots) const;
     size_t slotsAndStructSize() const { return slotsAndStructSize(numSlots()); }
diff --git a/js/src/vm/String.h b/js/src/vm/String.h
index 3a58b4efcbc6..53fd82f8a645 100644
--- a/js/src/vm/String.h
+++ b/js/src/vm/String.h
@@ -583,7 +583,7 @@ class JSExternalString : public JSFixedString
     intN externalType() const {
         JS_ASSERT(isExternal());
         JS_ASSERT(d.s.u2.externalType < TYPE_LIMIT);
-        return d.s.u2.externalType;
+        return intN(d.s.u2.externalType);
     }
 
     void *externalClosure() const {