Index: src/OFSelectKernelEventObserver.m
==================================================================
--- src/OFSelectKernelEventObserver.m
+++ src/OFSelectKernelEventObserver.m
@@ -48,21 +48,22 @@
 - (instancetype)init
 {
 	self = [super init];
 
 	@try {
+		FD_ZERO(&_readFDs);
+		FD_ZERO(&_writeFDs);
+
 #ifdef OF_AMIGAOS
 		_maxFD = 0;
 #else
 # ifndef OF_WINDOWS
 		if (_cancelFD[0] >= (int)FD_SETSIZE)
 			@throw [OFInitializationFailedException
 			    exceptionWithClass: self.class];
 # endif
 
-		FD_ZERO(&_readFDs);
-		FD_ZERO(&_writeFDs);
 		FD_SET(_cancelFD[0], &_readFDs);
 
 		if (_cancelFD[0] > INT_MAX)
 			@throw [OFOutOfRangeException exception];
 
@@ -170,11 +171,12 @@
 	fd_set readFDs;
 	fd_set writeFDs;
 	struct timeval timeout;
 	int events;
 #ifdef OF_AMIGAOS
-	ULONG execSignalMask, cancelSignal;
+	BYTE cancelSignal;
+	ULONG execSignalMask;
 #endif
 	void *pool;
 
 	if ([self of_processReadBuffers])
 		return;
@@ -199,11 +201,11 @@
 	timeout.tv_sec = (long)timeInterval;
 #endif
 	timeout.tv_usec = (int)((timeInterval - timeout.tv_sec) * 1000000);
 
 #ifdef OF_AMIGAOS
-	if ((cancelSignal = AllocSignal(-1)) == (ULONG)-1)
+	if ((cancelSignal = AllocSignal(-1)) == (BYTE)-1)
 		@throw [OFObserveFailedException exceptionWithObserver: self
 								 errNo: EAGAIN];
 
 	execSignalMask = _execSignalMask | (1ul << cancelSignal);