diff --git a/crypto/evp/m_sigver.c b/crypto/evp/m_sigver.c
index 85c1fa281a..829b861ed2 100644
--- a/crypto/evp/m_sigver.c
+++ b/crypto/evp/m_sigver.c
@@ -317,11 +317,13 @@ int EVP_DigestSignUpdate(EVP_MD_CTX *ctx, const void *data, size_t dsize)
                                                       data, dsize);
 
  legacy:
-    /* do_sigver_init() checked that |digest_custom| is non-NULL */
-    if (pctx->flag_call_digest_custom
-        && !ctx->pctx->pmeth->digest_custom(ctx->pctx, ctx))
-        return 0;
-    pctx->flag_call_digest_custom = 0;
+    if (pctx != NULL) {
+        /* do_sigver_init() checked that |digest_custom| is non-NULL */
+        if (pctx->flag_call_digest_custom
+            && !ctx->pctx->pmeth->digest_custom(ctx->pctx, ctx))
+            return 0;
+        pctx->flag_call_digest_custom = 0;
+    }
 
     return EVP_DigestUpdate(ctx, data, dsize);
 }