diff --git a/src/LinearMath/btThreads.h b/src/LinearMath/btThreads.h
index b592ec3e5..284702d71 100644
--- a/src/LinearMath/btThreads.h
+++ b/src/LinearMath/btThreads.h
@@ -79,6 +79,7 @@ const unsigned int BT_MAX_THREAD_COUNT = 64;
 SIMD_FORCE_INLINE void btMutexLock( btSpinMutex* ) {}
 SIMD_FORCE_INLINE void btMutexUnlock( btSpinMutex* ) {}
 SIMD_FORCE_INLINE bool btMutexTryLock( btSpinMutex* ) {return true;}
+SIMD_FORCE_INLINE bool btThreadsAreRunning() { return false;}
 #endif
 
 //