Index: src/OFThread.h
==================================================================
--- src/OFThread.h
+++ src/OFThread.h
@@ -53,10 +53,11 @@
  */
 @interface OFThread: OFObject
 {
 	id object;
 	of_thread_t thread;
+	BOOL running;
 
 @public
 	id retval;
 }
 

Index: src/OFThread.m
==================================================================
--- src/OFThread.m
+++ src/OFThread.m
@@ -65,13 +65,16 @@
 	self = [super init];
 	object = [obj copy];
 
 	if (!of_thread_new(&thread, call_main, self)) {
 		Class c = isa;
+		[object release];
 		[super dealloc];
 		@throw [OFInitializationFailedException newWithClass: c];
 	}
+
+	running = YES;
 
 	return self;
 }
 
 - main
@@ -80,10 +83,11 @@
 }
 
 - join
 {
 	of_thread_join(thread);
+	running = NO;
 
 	return retval;
 }
 
 - (void)dealloc
@@ -91,11 +95,12 @@
 	/*
 	 * No need to handle errors - if canceling the thread fails, we can't
 	 * do anything anyway. Most likely, it finished already or was already
 	 * canceled.
 	 */
-	of_thread_cancel(thread);
+	if (running)
+		of_thread_cancel(thread);
 
 	[object release];
 	[super dealloc];
 }
 @end