diff --git a/crypto/err/err.c b/crypto/err/err.c
index 5a79fb87..5a371a5e 100644
--- a/crypto/err/err.c
+++ b/crypto/err/err.c
@@ -279,6 +279,7 @@ void ERR_clear_error(void) {
   }
   if (state->to_free) {
     OPENSSL_free(state->to_free);
+    state->to_free = NULL;
   }
 
   state->top = state->bottom = 0;