diff --git a/src/ssl_sock.c b/src/ssl_sock.c
index e916605..f359e72 100644
--- a/src/ssl_sock.c
+++ b/src/ssl_sock.c
@@ -11455,6 +11455,10 @@
 		memprintf(&err, "certificate '%s' does not exist!", cert_path);
 		goto error;
 	}
+	if (store->multi) {
+		memprintf(&err, "certificate '%s' is a bundle. You can disable the bundle merging with the directive 'ssl-load-extra-files' in the global section.", cert_path);
+		goto error;
+	}
 	if (store->ckch == NULL || store->ckch->cert == NULL) {
 		memprintf(&err, "certificate '%s' is empty!", cert_path);
 		goto error;
@@ -11543,6 +11547,10 @@
 		memprintf(&err, "certificate '%s' does not exist!", cert_path);
 		goto error;
 	}
+	if (store->multi) {
+		memprintf(&err, "certificate '%s' is a bundle. You can disable the bundle merging with the directive 'ssl-load-extra-files' in the global section.", cert_path);
+		goto error;
+	}
 	if (store->ckch == NULL || store->ckch->cert == NULL) {
 		memprintf(&err, "certificate '%s' is empty!", cert_path);
 		goto error;