diff --git a/src/client.h b/src/client.h
index 38d20ede3e1ff800e61371c71c25a6f20ebacc21..16475c4bc9dd89955a5fd4b9209fff846b8e1f23 100644
--- a/src/client.h
+++ b/src/client.h
@@ -37,6 +37,7 @@ static const char *exe = "bin/client";
 
 /* Functions */
 static char *read_version_file(char *);
+void check_version(struct soap *, char *, char *);
 void availability(struct soap *, char *, char *, char *);
 
 #endif