diff --git a/src/tool_getparam.h b/src/tool_getparam.h
index 0cd2c3972c22f43bdf69484b8dc8eb21cf3d8609..7dc49393b7726dbc965ccb5f6b5dafc780fca8ef 100644
--- a/src/tool_getparam.h
+++ b/src/tool_getparam.h
@@ -37,6 +37,8 @@ typedef enum {
   PARAM_LAST
 } ParameterError;
 
+struct Configurable;
+
 ParameterError getparameter(char *flag,
                             char *nextarg,
                             bool *usedarg,