diff --git a/calmwm.h b/calmwm.h
index 849a803..9543341 100644
--- a/calmwm.h
+++ b/calmwm.h
@@ -74,6 +74,8 @@
 #define CWM_MENU_DUMMY		0x0001
 #define CWM_MENU_FILE		0x0002
 
+#define ARG_CHAR		0x0001
+#define ARG_INT			0x0002
 union arg {
 	char	*c;
 	int	 i;
@@ -239,6 +241,7 @@ struct keybinding {
 	int			 keycode;
 #define KBFLAG_NEEDCLIENT	 0x0001
 	int			 flags;
+	int			 argtype;
 };
 TAILQ_HEAD(keybinding_q, keybinding);
 
diff --git a/conf.c b/conf.c
index 2541f81..f583f78 100644
--- a/conf.c
+++ b/conf.c
@@ -470,14 +470,16 @@ conf_bindname(struct conf *c, char *name, char *binding)
 		current_binding->callback = name_to_kbfunc[i].handler;
 		current_binding->flags = name_to_kbfunc[i].flags;
 		current_binding->argument = name_to_kbfunc[i].argument;
+		current_binding->argtype |= ARG_INT;
 		conf_grab(c, current_binding);
 		TAILQ_INSERT_TAIL(&c->keybindingq, current_binding, entry);
 		return;
 	}
 
 	current_binding->callback = kbfunc_cmdexec;
-	current_binding->argument.c = xstrdup(binding);
 	current_binding->flags = 0;
+	current_binding->argument.c = xstrdup(binding);
+	current_binding->argtype |= ARG_CHAR;
 	conf_grab(c, current_binding);
 	TAILQ_INSERT_TAIL(&c->keybindingq, current_binding, entry);
 }
@@ -496,6 +498,8 @@ conf_unbind(struct conf *c, struct keybinding *unbind)
 		    key->keysym == unbind->keysym) {
 			conf_ungrab(c, key);
 			TAILQ_REMOVE(&c->keybindingq, key, entry);
+			if (key->argtype & ARG_CHAR)
+				free(key->argument.c);
 			free(key);
 		}
 	}