diff --git a/src/libCom/osi/osiSem.h b/src/libCom/osi/osiSem.h
index 96519c03f..cfca4d868 100644
--- a/src/libCom/osi/osiSem.h
+++ b/src/libCom/osi/osiSem.h
@@ -1,6 +1,8 @@
 #ifndef osiSemh
 #define osiSemh
 
+#include <assert.h>
+
 #ifdef __cplusplus
 extern "C" {
 #endif
@@ -12,32 +14,58 @@ typedef enum {semTakeOK,semTakeTimeout,semTakeError} semTakeStatus;
 typedef enum {semEmpty,semFull} semInitialState;
 
 epicsShareFunc semId epicsShareAPI semBinaryCreate(int initialState);
-epicsShareFunc semId epicsShareAPI semBinaryMustCreate(int initialState);
+static INLINE semId semBinaryMustCreate (int initialState);
 epicsShareFunc void epicsShareAPI semBinaryDestroy(semId id);
 epicsShareFunc void epicsShareAPI semBinaryGive(semId id);
 epicsShareFunc semTakeStatus epicsShareAPI semBinaryTake(semId id);
-epicsShareFunc void epicsShareAPI semBinaryMustTake(semId id);
+static INLINE void semBinaryMustTake (semId id);
 epicsShareFunc semTakeStatus epicsShareAPI semBinaryTakeTimeout(semId id, double timeOut);
 epicsShareFunc semTakeStatus epicsShareAPI semBinaryTakeNoWait(semId id);
 epicsShareFunc void epicsShareAPI semBinaryShow(semId id);
 
 epicsShareFunc semId epicsShareAPI semMutexCreate(void);
-epicsShareFunc semId epicsShareAPI semMutexMustCreate(void);
+static INLINE semId semMutexMustCreate (void);
 epicsShareFunc void epicsShareAPI semMutexDestroy(semId id);
 epicsShareFunc void epicsShareAPI semMutexGive(semId id);
 epicsShareFunc semTakeStatus epicsShareAPI semMutexTake(semId id);
-epicsShareFunc void epicsShareAPI semMutexMustTake(semId id);
+static INLINE void semMutexMustTake(semId id);
 epicsShareFunc semTakeStatus epicsShareAPI semMutexTakeTimeout(semId id, double timeOut);
 epicsShareFunc semTakeStatus epicsShareAPI semMutexTakeNoWait(semId id);
 epicsShareFunc void epicsShareAPI semMutexShow(semId id);
 
-#ifdef __cplusplus
-}
-#endif
-
 /*NOTES:
     Mutex semaphores MUST implement recursive locking
     Mutex semaphores should implement priority inheritance and deletion safe
 */
 
+static INLINE semId semBinaryMustCreate (int initialState)
+{
+    semId id = semBinaryCreate (initialState);
+    assert (id);
+    return id;
+}
+
+static INLINE void semBinaryMustTake (semId id)
+{
+    assert (semBinaryTake (id)==semTakeOK);
+}
+
+static INLINE semId semMutexMustCreate (void)
+{
+    semId id = semMutexCreate ();
+    assert (id);
+    return id;
+}
+
+static INLINE void semMutexMustTake(semId id)
+{
+    assert (semMutexTake (id)==semTakeOK);
+}
+
+
+#ifdef __cplusplus
+}
+#endif
+
+
 #endif /* osiSemh */