diff --git a/js/src/dtoa.c b/js/src/dtoa.c
index 1fdd397fb779..5c4128ef5dc3 100644
--- a/js/src/dtoa.c
+++ b/js/src/dtoa.c
@@ -1266,10 +1266,6 @@ d2b
 		    b->wds = (x[1] = z) ? 2 : 1;
 		}
 	else {
-#ifdef DEBUG
-		if (!z)
-			Bug("Zero passed to d2b");
-#endif
 		k = lo0bits(&z);
 		x[0] = z;
 #ifndef Sudden_Underflow