diff --git a/js/src/jit/Recover.h b/js/src/jit/Recover.h
--- a/js/src/jit/Recover.h
+++ b/js/src/jit/Recover.h
@@ -560,29 +560,29 @@ class RStringSplit final : public RInstr
 };
 
 class RRegExpMatcher final : public RInstruction
 {
   public:
     RINSTRUCTION_HEADER_(RegExpMatcher)
 
     virtual uint32_t numOperands() const {
-        return 5;
+        return 4;
     }
 
     bool recover(JSContext* cx, SnapshotIterator& iter) const;
 };
 
 class RRegExpTester final : public RInstruction
 {
   public:
     RINSTRUCTION_HEADER_(RegExpTester)
 
     virtual uint32_t numOperands() const {
-        return 5;
+        return 4;
     }
 
     bool recover(JSContext* cx, SnapshotIterator& iter) const;
 };
 
 class RRegExpReplace final : public RInstruction
 {
   public:
