diff --git a/src/tool_operhlp.h b/src/tool_operhlp.h
index 041ea596847971e1f7e771bfa937f955e1c2ae74..80a7682e489a4265af07b7a655d9b8db893557c8 100644
--- a/src/tool_operhlp.h
+++ b/src/tool_operhlp.h
@@ -23,6 +23,8 @@
  ***************************************************************************/
 #include "tool_setup.h"
 
+struct Configurable;
+
 void clean_getout(struct Configurable *config);
 
 bool output_expected(const char *url, const char *uploadfile);