diff --git a/Lib/sre_compile.py b/Lib/sre_compile.py
index d3eb3c1e5f3..1d448dae2ac 100644
--- a/Lib/sre_compile.py
+++ b/Lib/sre_compile.py
@@ -167,7 +167,7 @@ def _compile(code, pattern, flags):
             emit(av-1)
         elif op is GROUPREF_EXISTS:
             emit(OPCODES[op])
-            emit((av[0]-1)*2)
+            emit(av[0]-1)
             skipyes = _len(code); emit(0)
             _compile(code, av[1], flags)
             if av[2]: