diff --git a/src/lib/protocols/http.c b/src/lib/protocols/http.c
index 6951dd85cf5..27140905727 100644
--- a/src/lib/protocols/http.c
+++ b/src/lib/protocols/http.c
@@ -295,10 +295,12 @@ static ndpi_protocol_category_t ndpi_http_check_content(struct ndpi_detection_mo
 	if(packet->content_disposition_line.ptr[attachment_len] == '\"') {
 	  if(packet->content_disposition_line.ptr[packet->content_disposition_line.len-1] != '\"') {
 	    //case: filename="file_name
-	    flow->http.filename = ndpi_malloc(filename_len);
-	    if(flow->http.filename != NULL) {
-	      strncpy(flow->http.filename, (char*)packet->content_disposition_line.ptr+attachment_len+1, filename_len-1);
-	      flow->http.filename[filename_len-1] = '\0';
+	    if(filename_len >= 2) {
+	      flow->http.filename = ndpi_malloc(filename_len);
+	      if(flow->http.filename != NULL) {
+	        strncpy(flow->http.filename, (char*)packet->content_disposition_line.ptr+attachment_len+1, filename_len-1);
+	        flow->http.filename[filename_len-1] = '\0';
+	      }
 	    }
 	  }
 	  else if(filename_len >= 2) {