diff --git a/common/include/dxxerror.h b/common/include/dxxerror.h
index 7c09923fa..3e7a0fbeb 100644
--- a/common/include/dxxerror.h
+++ b/common/include/dxxerror.h
@@ -35,7 +35,7 @@ int error_init(void (*func)(char *), char *fmt,...);    //init error system, set
 void set_exit_message(char *fmt,...);	//specify message to print at exit
 void Warning(char *fmt,...);				//print out warning message to user
 void set_warn_func(void (*f)(char *s));//specifies the function to call with warning messages
-void clear_warn_func(void (*f)(char *s));//say this function no longer valid
+void clear_warn_func();//say this function no longer valid
 void _Assert(int expr,char *expr_text,char *filename,int linenum);	//assert func
 void Error(const char *fmt,...) __noreturn __attribute_gcc_format((printf, 1, 2));				//exit with error code=1, print message
 void Assert(int expr);
diff --git a/common/misc/error.c b/common/misc/error.c
index 10efa3543..8b7d55749 100644
--- a/common/misc/error.c
+++ b/common/misc/error.c
@@ -52,7 +52,7 @@ void set_warn_func(void (*f)(char *s))
 }
 
 //uninstall warning function - install default printf
-void clear_warn_func(void (*f)(char *s))
+void clear_warn_func()
 {
 	warn_func = warn_printf;
 }
diff --git a/similar/editor/med.c b/similar/editor/med.c
index 758c195ca..0ce970f6e 100644
--- a/similar/editor/med.c
+++ b/similar/editor/med.c
@@ -960,7 +960,7 @@ void close_editor() {
 #ifndef __LINUX__
 	set_warn_func(msgbox_warning);
 #else
-	clear_warn_func(NULL);
+	clear_warn_func();
 #endif
 	
 	close_editor_screen();