diff --git a/src/misc.c b/src/misc.c
index 74a6d5a7..a262e09d 100644
--- a/src/misc.c
+++ b/src/misc.c
@@ -834,7 +834,7 @@ int _libssh2_get_string(struct string_buf *buf, unsigned char **outbuf,
                         size_t *outlen)
 {
     uint32_t data_len;
-    if(_libssh2_get_u32(buf, &data_len) != 0) {
+    if(!buf || _libssh2_get_u32(buf, &data_len) != 0) {
         return -1;
     }
     if(!_libssh2_check_length(buf, data_len)) {