diff --git a/C/absmi.c b/C/absmi.c
index 8074bd799..02f1b3fa7 100644
--- a/C/absmi.c
+++ b/C/absmi.c
@@ -1083,8 +1083,8 @@ Yap_absmi(int inp)
       READ_LOCK(PP->PRWLock);
       if (PP->cs.p_code.TrueCodeOfPred != PREG) {
 	PREG = PP->cs.p_code.TrueCodeOfPred;
-	PP = NULL;
 	READ_UNLOCK(PP->PRWLock);
+	PP = NULL;
 	GONext();
       }
 #endif