@@ -50,13 +50,11 @@
 #import "OFLocale.h"
 #import "OFString.h"
 
 #import "OFNotImplementedException.h"
 
-#ifdef OF_HAVE_THREADS
-# import "threading.h"
-#endif
+#import "once.h"
 
 #if defined(OF_MACOS) || defined(OF_IOS)
 # ifdef HAVE_SYSDIR_H
 #  include <sysdir.h>
 # endif
@@ -340,36 +338,20 @@
 	return OBJFW_VERSION_MINOR;
 }
 
 + (OFString *)operatingSystemName
 {
-#ifdef OF_HAVE_THREADS
 	static of_once_t onceControl = OF_ONCE_INIT;
 	of_once(&onceControl, initOperatingSystemName);
-#else
-	static bool initialized = false;
-	if (!initialized) {
-		initOperatingSystemName();
-		initialized = true;
-	}
-#endif
 
 	return operatingSystemName;
 }
 
 + (OFString *)operatingSystemVersion
 {
-#ifdef OF_HAVE_THREADS
 	static of_once_t onceControl = OF_ONCE_INIT;
 	of_once(&onceControl, initOperatingSystemVersion);
-#else
-	static bool initialized = false;
-	if (!initialized) {
-		initOperatingSystemVersion();
-		initialized = true;
-	}
-#endif
 
 	return operatingSystemVersion;
 }
 
 #ifdef OF_HAVE_FILES