diff --git a/js/src/jsnum.c b/js/src/jsnum.c
index b2abb853c62c..c569dc523e1e 100644
--- a/js/src/jsnum.c
+++ b/js/src/jsnum.c
@@ -438,7 +438,11 @@ static JSConstDoubleSpec number_constants[] = {
 
 static jsdouble NaN;
 
-#if !defined __MWERKS__ && defined XP_PC && (defined _M_IX86 || (defined __GNUC__ && !defined(__MINGW32__)))
+
+#if defined XP_PC &&                                                          \
+    !defined __MWERKS__ &&                                                    \
+    (defined _M_IX86 ||                                                       \
+    (defined __GNUC__ && !defined __MINGW32__ && !defined __EMX__))
 
 /*
  * Set the exception mask to mask all exceptions and set the FPU precision