diff --git a/darwin/main.m b/darwin/main.m
index 0bdb2965..2aef0af0 100644
--- a/darwin/main.m
+++ b/darwin/main.m
@@ -244,6 +244,42 @@ void uiQueueMain(void (*f)(void *data), void *data)
 	dispatch_async_f(dispatch_get_main_queue(), data, f);
 }
 
+@interface TimerDelegate : NSObject {
+        int (*f)(void *data);
+        void *data;
+}
+- (id)initWithCallback:(int (*)(void *))callback data:(void*)callbackData;
+- (void)doTimer:(NSTimer *)timer;
+@end
+
+@implementation TimerDelegate
+
+- (id)initWithCallback:(int (*)(void *))callback data:(void*)callbackData
+{
+        self = [super init];
+        if (self) {
+                f = callback;
+                data = callbackData;
+        }
+        return self;
+}
+
+- (void)doTimer:(NSTimer *)timer
+{
+        if (!f(data))
+                [timer invalidate];
+}
+
+@end
+
 void uiTimer(int milliseconds, int (*f)(void *data), void *data)
 {
+        TimerDelegate *delegate;
+
+        delegate = [[TimerDelegate alloc] initWithCallback:f data:data];
+        [NSTimer scheduledTimerWithTimeInterval:milliseconds / 1000.0
+                target:delegate
+                selector:@selector(doTimer:)
+                userInfo:nil
+                repeats:YES];
 }
diff --git a/unix/main.c b/unix/main.c
index 1047f5c5..ec3182db 100644
--- a/unix/main.c
+++ b/unix/main.c
@@ -107,6 +107,29 @@ void uiQueueMain(void (*f)(void *data), void *data)
 	gdk_threads_add_idle(doqueued, q);
 }
 
+struct timer {
+        int (*f)(void *);
+        void *data;
+};
+
+static gboolean dotimer(gpointer data)
+{
+        struct timer *t = (struct timer *) data;
+
+        if((*(t->f))(t->data))
+                return TRUE;
+        else {
+                g_free(t);
+                return FALSE;
+        }
+}
+
 void uiTimer(int milliseconds, int (*f)(void *data), void *data)
 {
+        struct timer *t;
+
+        t = g_new0(struct timer, 1);
+        t->f = f;
+        t->data = data;
+        g_timeout_add(milliseconds, dotimer, t);
 }