diff --git a/js/src/jstracer.h b/js/src/jstracer.h
index cacacbc51559..91288fe2eb99 100755
--- a/js/src/jstracer.h
+++ b/js/src/jstracer.h
@@ -202,7 +202,7 @@ public:
     void            clear();
 };
 
-#if defined(JS_JIT_SPEW) || defined(MOZ_NO_VARADIC_MACROS)
+#if defined(JS_JIT_SPEW) || defined(NJ_NO_VARIADIC_MACROS)
 
 enum LC_TMBits {
     /*
@@ -220,7 +220,7 @@ enum LC_TMBits {
 
 #endif
 
-#ifdef MOZ_NO_VARADIC_MACROS
+#ifdef NJ_NO_VARIADIC_MACROS
 
 #define debug_only_stmt(action)            /* */
 static void debug_only_printf(int mask, const char *fmt, ...) {}
diff --git a/js/src/jstypes.h b/js/src/jstypes.h
index 17183e24c5f6..f6b49f49d65b 100644
--- a/js/src/jstypes.h
+++ b/js/src/jstypes.h
@@ -296,7 +296,7 @@
 #ifdef _MSC_VER
 # include "jscpucfg.h"  /* We can't auto-detect MSVC configuration */
 # if _MSC_VER < 1400
-#  define MOZ_NO_VARADIC_MACROS
+#  define NJ_NO_VARIADIC_MACROS
 # endif
 #else
 # include "jsautocfg.h" /* Use auto-detected configuration */
diff --git a/js/src/nanojit/Native.h b/js/src/nanojit/Native.h
index e7d1019babe4..cf21f621fb4a 100644
--- a/js/src/nanojit/Native.h
+++ b/js/src/nanojit/Native.h
@@ -110,7 +110,7 @@ namespace nanojit {
 
     #define isSPorFP(r)     ( (r)==SP || (r)==FP )
 
-    #ifdef MOZ_NO_VARADIC_MACROS
+    #ifdef NJ_NO_VARIADIC_MACROS
         static void asm_output(const char *f, ...) {}
         #define gpn(r)                    regNames[(r)]
         #define fpn(r)                    regNames[(r)]
diff --git a/js/src/nanojit/VMPI.h b/js/src/nanojit/VMPI.h
index 5d8d3808e8e5..83353623f6eb 100644
--- a/js/src/nanojit/VMPI.h
+++ b/js/src/nanojit/VMPI.h
@@ -56,6 +56,7 @@
 #include <ctype.h>
 #include <stdlib.h>
 #include <stddef.h>
+#include <stdarg.h>
 
 #if defined(AVMPLUS_UNIX) || defined(AVMPLUS_OS2)
 #include <unistd.h>
@@ -84,6 +85,7 @@ typedef unsigned __int64 uint64_t;
 #define VMPI_strncat strncat
 #define VMPI_strcpy strcpy
 #define VMPI_sprintf sprintf
+#define VMPI_vfprintf vfprintf
 #define VMPI_memset memset
 #define VMPI_isdigit isdigit
 #define VMPI_getDate()
diff --git a/js/src/nanojit/avmplus.cpp b/js/src/nanojit/avmplus.cpp
index c292bce99ba4..aa26b64d85fd 100644
--- a/js/src/nanojit/avmplus.cpp
+++ b/js/src/nanojit/avmplus.cpp
@@ -51,6 +51,10 @@ Config AvmCore::config;
 
 void
 avmplus::AvmLog(char const *msg, ...) {
+    va_list ap;
+    va_start(ap, msg);
+    VMPI_vfprintf(stderr, msg, ap);
+    va_end(ap);
 }
 
 #ifdef _DEBUG
diff --git a/js/src/nanojit/avmplus.h b/js/src/nanojit/avmplus.h
index a383675dd84e..def8ac6ed465 100644
--- a/js/src/nanojit/avmplus.h
+++ b/js/src/nanojit/avmplus.h
@@ -85,7 +85,7 @@ static inline bool blx_lr_broken() {
 #include <os2.h>
 #endif
 
-#if defined(DEBUG) || defined(MOZ_NO_VARADIC_MACROS)
+#if defined(DEBUG) || defined(NJ_NO_VARIADIC_MACROS)
 #if !defined _DEBUG
 #define _DEBUG
 #endif
diff --git a/js/src/nanojit/nanojit.h b/js/src/nanojit/nanojit.h
index e33bb4a9fc77..9190e9561196 100644
--- a/js/src/nanojit/nanojit.h
+++ b/js/src/nanojit/nanojit.h
@@ -91,15 +91,15 @@ namespace nanojit
 
     const uint32_t MAXARGS = 8;
 
-    #ifdef MOZ_NO_VARADIC_MACROS
-        static void NanoAssertMsgf(bool a,const char *f,...) {}
-        static void NanoAssertMsg(bool a,const char *m) {}
-        static void NanoAssert(bool a) {}
+    #ifdef NJ_NO_VARIADIC_MACROS
+        inline void NanoAssertMsgf(bool a,const char *f,...) {}
+        inline void NanoAssertMsg(bool a,const char *m) {}
+        inline void NanoAssert(bool a) {}
     #elif defined(_DEBUG)
 
         #define __NanoAssertMsgf(a, file_, line_, f, ...)  \
             if (!(a)) { \
-                fprintf(stderr, "Assertion failed: " f "%s (%s:%d)\n", __VA_ARGS__, #a, file_, line_); \
+                avmplus::AvmLog("Assertion failed: " f "%s (%s:%d)\n", __VA_ARGS__, #a, file_, line_); \
                 NanoAssertFail(); \
             }
 
@@ -144,7 +144,7 @@ namespace nanojit
 #endif
 #endif
 
-#ifdef MOZ_NO_VARADIC_MACROS
+#ifdef NJ_NO_VARIADIC_MACROS
     #include <stdio.h>
     #define verbose_outputf            if (_logc->lcbits & LC_Assembly) \
                                         Assembler::outputf