diff --git a/crypto/evp/m_sigver.c b/crypto/evp/m_sigver.c
index d296ef113f..a79d656804 100644
--- a/crypto/evp/m_sigver.c
+++ b/crypto/evp/m_sigver.c
@@ -131,7 +131,9 @@ static int do_sigver_init(EVP_MD_CTX *ctx, EVP_PKEY_CTX **pctx,
          * iteration we're on.
          */
         EVP_SIGNATURE_free(signature);
+        signature = NULL;
         EVP_KEYMGMT_free(tmp_keymgmt);
+        tmp_keymgmt = NULL;
 
         switch (iter) {
         case 1: