diff --git a/mozilla/js/src/jsopcode.c b/mozilla/js/src/jsopcode.c
index 5b4d82f7687..fb549655219 100644
--- a/mozilla/js/src/jsopcode.c
+++ b/mozilla/js/src/jsopcode.c
@@ -2065,11 +2065,22 @@ Decompile(SprintStack *ss, jsbytecode *pc, intN nb)
                                 goto do_forloop;
                             }
                             if (SN_TYPE(sn) == SRC_DECL) {
-                                todo = SprintCString(&ss->sprinter, rval);
-                                if (todo < 0 ||
-                                    !PushOff(ss, todo, JSOP_NOP)) {
-                                    return NULL;
+                                if (ss->top == jp->script->depth) {
+                                    /*
+                                     * This must be an empty destructuring
+                                     * in the head of a let whose body block
+                                     * is also empty.
+                                     */
+                                    pc = pc2 + 1;
+                                    len = js_GetSrcNoteOffset(sn, 0);
+                                    LOCAL_ASSERT(pc[len] == JSOP_LEAVEBLOCK);
+                                    js_printf(jp, "\tlet (%s) {\n", rval);
+                                    js_printf(jp, "\t}\n");
+                                    goto end_setsp;
                                 }
+                                todo = SprintCString(&ss->sprinter, rval);
+                                if (todo < 0 || !PushOff(ss, todo, JSOP_NOP))
+                                    return NULL;
                                 op = JSOP_POP;
                                 pc = pc2 + 1;
                                 goto do_letheadbody;
@@ -2091,9 +2102,11 @@ Decompile(SprintStack *ss, jsbytecode *pc, intN nb)
 
                     /*
                      * If control flow reaches this point with todo still -2,
+                     * just print rval as an expression statement.
                      */
                     if (todo == -2)
                         js_printf(jp, "\t%s;\n", rval);
+                  end_setsp:
                     break;
                 }
 #endif