diff --git a/js/src/jsobj.c b/js/src/jsobj.c
index 1ecbccd3c7a..b6f5186ee89 100644
--- a/js/src/jsobj.c
+++ b/js/src/jsobj.c
@@ -1128,7 +1128,8 @@ obj_eval(JSContext *cx, JSObject *obj, uintN argc, jsval *argv, jsval *rval)
         rt = cx->runtime;
         if (rt->findObjectPrincipals) {
             scopePrincipals = rt->findObjectPrincipals(cx, scopeobj);
-            if (!principals->subsume(principals, scopePrincipals)) {
+            if (scopePrincipals &&
+                !principals->subsume(principals, scopePrincipals)) {
                 JS_ReportErrorNumber(cx, js_GetErrorMessage, NULL,
                                      JSMSG_BAD_INDIRECT_CALL, js_eval_str);
                 return JS_FALSE;
diff --git a/js/src/jsscript.c b/js/src/jsscript.c
index ed4e93b8d0f..131964bc0a9 100644
--- a/js/src/jsscript.c
+++ b/js/src/jsscript.c
@@ -306,7 +306,8 @@ script_exec(JSContext *cx, JSObject *obj, uintN argc, jsval *argv, jsval *rval)
         rt = cx->runtime;
         if (rt->findObjectPrincipals) {
             scopePrincipals = rt->findObjectPrincipals(cx, scopeobj);
-            if (!principals->subsume(principals, scopePrincipals)) {
+            if (scopePrincipals &&
+                !principals->subsume(principals, scopePrincipals)) {
                 JS_ReportErrorNumber(cx, js_GetErrorMessage, NULL,
                                      JSMSG_BAD_INDIRECT_CALL,
                                      "Script.prototype.exec");