diff --git a/js/xpconnect/src/XPCConvert.cpp b/js/xpconnect/src/XPCConvert.cpp
index 700f6f956edb..0ac11b4d2b7f 100644
--- a/js/xpconnect/src/XPCConvert.cpp
+++ b/js/xpconnect/src/XPCConvert.cpp
@@ -147,11 +147,6 @@ XPCConvert::RemoveXPCOMUCStringFinalizer()
     sXPCOMUCStringFinalizerIndex = -1;
 }
 
-
-#define FIT_U32(i)     ((i) <= JSVAL_INT_MAX                                  \
-                        ? INT_TO_JSVAL(i)                                     \
-                        : DOUBLE_TO_JSVAL(i))
-
 // static
 JSBool
 XPCConvert::NativeData2JS(XPCLazyCallContext& lccx, jsval* d, const void* s,
@@ -176,9 +171,9 @@ XPCConvert::NativeData2JS(XPCLazyCallContext& lccx, jsval* d, const void* s,
     case nsXPTType::T_I16   : *d = INT_TO_JSVAL(int32_t(*((int16_t*)s)));            break;
     case nsXPTType::T_I32   : *d = INT_TO_JSVAL(*((int32_t*)s));                     break;
     case nsXPTType::T_I64   : *d = DOUBLE_TO_JSVAL(jsdouble(*((int64_t*)s)));        break;
-    case nsXPTType::T_U8    : *d = INT_TO_JSVAL(int32_t(*((uint8*)s)));              break;
+    case nsXPTType::T_U8    : *d = INT_TO_JSVAL(int32_t(*((uint8_t*)s)));            break;
     case nsXPTType::T_U16   : *d = INT_TO_JSVAL(int32_t(*((uint16_t*)s)));           break;
-    case nsXPTType::T_U32   : *d = FIT_U32(*((uint32_t*)s));                         break;
+    case nsXPTType::T_U32   : *d = UINT_TO_JSVAL(*((uint32_t*)s));                   break;
     case nsXPTType::T_U64   : *d = DOUBLE_TO_JSVAL(jsdouble(*((uint64_t*)s)));       break;
     case nsXPTType::T_FLOAT : *d = DOUBLE_TO_JSVAL(*((float*)s));                    break;
     case nsXPTType::T_DOUBLE: *d = DOUBLE_TO_JSVAL(*((double*)s));                   break;