diff --git a/src/match_basic.c b/src/match_basic.c
index 85c3cad..1085525 100644
--- a/src/match_basic.c
+++ b/src/match_basic.c
@@ -22,7 +22,7 @@ candidates (const Knowledge know)
 
 struct fvpass
 {
-  int (*solution) (struct fvpass, Knowledge);
+  int (*solution)();
 
   System sys;
   int run;
diff --git a/src/match_clp.c b/src/match_clp.c
index bd62e13..97d1c37 100644
--- a/src/match_clp.c
+++ b/src/match_clp.c
@@ -21,7 +21,7 @@
 
 struct solvepass
 {
-  int (*solution) (struct solvepass, Constraintlist);
+  int (*solution)();
 
   System sys;
   int run;