Index: configure.ac
==================================================================
--- configure.ac
+++ configure.ac
@@ -571,16 +571,11 @@
 	AC_DEFINE(OF_HAVE_ATOMIC_OPS, 1, [Whether we have atomic operations])
 	AC_SUBST(ATOMIC_H, "atomic.h")
 ])
 AC_MSG_RESULT($atomic_ops)
 
-AC_CHECK_FUNC(gmtime_r, [
-	AC_DEFINE(HAVE_GMTIME_R, 1, [Whether we have gmtime_r])
-])
-AC_CHECK_FUNC(localtime_r, [
-	AC_DEFINE(HAVE_LOCALTIME_R, 1, [Whether we have localtime_r])
-])
+AC_CHECK_FUNCS([gmtime_r localtime_r nanosleep])
 
 AC_ARG_ENABLE(sockets,
 	AS_HELP_STRING([--disable-sockets], [disable socket support]))
 AS_IF([test x"$enable_sockets" != x"no"], [
 	AC_DEFINE(OF_HAVE_SOCKETS, 1, [Whether we have sockets])

Index: src/OFThread.m
==================================================================
--- src/OFThread.m
+++ src/OFThread.m
@@ -20,10 +20,11 @@
 
 #define __NO_EXT_QNX
 
 #include <stdlib.h>
 #include <math.h>
+#include <time.h>
 
 #ifndef _WIN32
 # include <unistd.h>
 #endif
 
@@ -182,16 +183,26 @@
 + (void)sleepForTimeInterval: (double)seconds
 {
 	if (seconds < 0)
 		@throw [OFOutOfRangeException exceptionWithClass: self];
 
-#ifndef _WIN32
+#if defined(HAVE_NANOSLEEP)
+	struct timespec rqtp;
+
+	rqtp.tv_sec = (time_t)seconds;
+	rqtp.tv_nsec = lrint((seconds - rqtp.tv_sec) * 1000000000);
+
+	if (rqtp.tv_sec != floor(seconds))
+		@throw [OFOutOfRangeException exceptionWithClass: self];
+
+	nanosleep(&rqtp, NULL);
+#elif !defined(_WIN32)
 	if (seconds > UINT_MAX)
 		@throw [OFOutOfRangeException exceptionWithClass: self];
 
 	sleep((unsigned int)seconds);
-	usleep((useconds_t)rint((seconds - floor(seconds)) * 1000000));
+	usleep((useconds_t)lrint((seconds - floor(seconds)) * 1000000));
 #else
 	if (seconds * 1000 > UINT_MAX)
 		@throw [OFOutOfRangeException exceptionWithClass: self];
 
 	Sleep((unsigned int)(seconds * 1000));
@@ -198,24 +209,11 @@
 #endif
 }
 
 + (void)sleepUntilDate: (OFDate*)date
 {
-	double seconds = [date timeIntervalSinceNow];
-
-#ifndef _WIN32
-	if (seconds > UINT_MAX)
-		@throw [OFOutOfRangeException exceptionWithClass: self];
-
-	sleep((unsigned int)seconds);
-	usleep((useconds_t)rint((seconds - floor(seconds)) * 1000000));
-#else
-	if (seconds * 1000 > UINT_MAX)
-		@throw [OFOutOfRangeException exceptionWithClass: self];
-
-	Sleep((unsigned int)(seconds * 1000));
-#endif
+	[self sleepForTimeInterval: [date timeIntervalSinceNow]];
 }
 
 + (void)yield
 {
 #ifdef OF_HAVE_SCHED_YIELD

Index: src/exceptions/OFConditionBroadcastFailedException.h
==================================================================
--- src/exceptions/OFConditionBroadcastFailedException.h
+++ src/exceptions/OFConditionBroadcastFailedException.h
@@ -13,10 +13,14 @@
  * LICENSE.GPLv2 or LICENSE.GPLv3 respectively included in the packaging of this
  * file.
  */
 
 #import "OFException.h"
+
+#ifndef OF_HAVE_THREADS
+# error No threads available!
+#endif
 
 @class OFCondition;
 
 /*!
  * @brief An exception indicating broadcasting a condition failed.

Index: src/exceptions/OFConditionSignalFailedException.h
==================================================================
--- src/exceptions/OFConditionSignalFailedException.h
+++ src/exceptions/OFConditionSignalFailedException.h
@@ -13,10 +13,14 @@
  * LICENSE.GPLv2 or LICENSE.GPLv3 respectively included in the packaging of this
  * file.
  */
 
 #import "OFException.h"
+
+#ifndef OF_HAVE_THREADS
+# error No threads available!
+#endif
 
 @class OFCondition;
 
 /*!
  * @brief An exception indicating signaling a condition failed.

Index: src/exceptions/OFConditionStillWaitingException.h
==================================================================
--- src/exceptions/OFConditionStillWaitingException.h
+++ src/exceptions/OFConditionStillWaitingException.h
@@ -13,10 +13,14 @@
  * LICENSE.GPLv2 or LICENSE.GPLv3 respectively included in the packaging of this
  * file.
  */
 
 #import "OFException.h"
+
+#ifndef OF_HAVE_THREADS
+# error No threads available!
+#endif
 
 @class OFCondition;
 
 /*!
  * @brief An exception indicating that a thread is still waiting for a

Index: src/exceptions/OFConditionWaitFailedException.h
==================================================================
--- src/exceptions/OFConditionWaitFailedException.h
+++ src/exceptions/OFConditionWaitFailedException.h
@@ -13,10 +13,14 @@
  * LICENSE.GPLv2 or LICENSE.GPLv3 respectively included in the packaging of this
  * file.
  */
 
 #import "OFException.h"
+
+#ifndef OF_HAVE_THREADS
+# error No threads available!
+#endif
 
 @class OFCondition;
 
 /*!
  * @brief An exception indicating waiting for a condition failed.

Index: src/exceptions/OFThreadJoinFailedException.h
==================================================================
--- src/exceptions/OFThreadJoinFailedException.h
+++ src/exceptions/OFThreadJoinFailedException.h
@@ -13,10 +13,14 @@
  * LICENSE.GPLv2 or LICENSE.GPLv3 respectively included in the packaging of this
  * file.
  */
 
 #import "OFException.h"
+
+#ifndef OF_HAVE_THREADS
+# error No threads available!
+#endif
 
 @class OFThread;
 
 /*!
  * @brief An exception indicating that joining a thread failed.

Index: src/exceptions/OFThreadStartFailedException.h
==================================================================
--- src/exceptions/OFThreadStartFailedException.h
+++ src/exceptions/OFThreadStartFailedException.h
@@ -13,10 +13,14 @@
  * LICENSE.GPLv2 or LICENSE.GPLv3 respectively included in the packaging of this
  * file.
  */
 
 #import "OFException.h"
+
+#ifndef OF_HAVE_THREADS
+# error No threads available!
+#endif
 
 @class OFThread;
 
 /*!
  * @brief An exception indicating that starting a thread failed.

Index: src/exceptions/OFThreadStillRunningException.h
==================================================================
--- src/exceptions/OFThreadStillRunningException.h
+++ src/exceptions/OFThreadStillRunningException.h
@@ -13,10 +13,14 @@
  * LICENSE.GPLv2 or LICENSE.GPLv3 respectively included in the packaging of this
  * file.
  */
 
 #import "OFException.h"
+
+#ifndef OF_HAVE_THREADS
+# error No threads available!
+#endif
 
 @class OFThread;
 
 /*!
  * @brief An exception indicating that a thread is still running.