diff --git a/src/xpdev/semwrap.h b/src/xpdev/semwrap.h
index a88f47a87ac4db143452196d2273353eac6e5b91..3e506c572797bc159b664ec587fa30da669f56cd 100644
--- a/src/xpdev/semwrap.h
+++ b/src/xpdev/semwrap.h
@@ -61,6 +61,7 @@ extern "C" {
 		#include <semaphore.h>	/* POSIX semaphores */
 	#endif
 
+	/* NOT POSIX */
 	int 	sem_trywait_block(sem_t *sem, unsigned long timeout);
 
 #elif defined(_WIN32)	
@@ -78,6 +79,7 @@ extern "C" {
 	#define sem_destroy(psem)			CloseHandle(*(psem))
 	/* No Win32 implementation for sem_getvalue() */
 
+	/* NOT POSIX */
 	#define sem_trywait_block(psem,t)	(WaitForSingleObject(*(psem),t)==WAIT_OBJECT_0?0:(errno=EAGAIN,-1))
 
 #elif defined(__OS2__)	/* These have *not* been tested! */
@@ -95,6 +97,9 @@ extern "C" {
 
 #endif
 
+/* Change semaphore to "unsignaled" (NOT POSIX) */
+#define sem_reset(psem)					while(sem_trywait(psem)==0)
+
 #if defined(__cplusplus)
 }
 #endif