diff --git a/mozilla/js/src/jsregexp.c b/mozilla/js/src/jsregexp.c
index 5a13a520c97..37e2a621ffe 100644
--- a/mozilla/js/src/jsregexp.c
+++ b/mozilla/js/src/jsregexp.c
@@ -2504,7 +2504,8 @@ ExecuteREBytecode(REGlobalData *gData, REMatchState *x)
                 pc += ARG_LEN;                 /* start of ASSERT child */
                 op = (REOp) *pc++;
                 if (REOP_IS_SIMPLE(op) &&
-                    !SimpleMatch(gData, x, op, &pc, JS_FALSE)) {
+                    (!SimpleMatch(gData, x, op, &pc, JS_FALSE) ||
+                     pc != nextpc)) {
                     result = NULL;
                     break;
                 }
@@ -2524,7 +2525,8 @@ ExecuteREBytecode(REGlobalData *gData, REMatchState *x)
                 pc += ARG_LEN;
                 op = (REOp) *pc++;
                 if (REOP_IS_SIMPLE(op) /* Note - fail to fail! */ &&
-                    SimpleMatch(gData, x, op, &pc, JS_FALSE)) {
+                    SimpleMatch(gData, x, op, &pc, JS_FALSE) &&
+                    pc == nextpc) {
                     result = NULL;
                     break;
                 }