diff --git a/dtool/src/dtoolbase/mutexImpl.h b/dtool/src/dtoolbase/mutexImpl.h
index 84da41dc72..b86c3709b3 100644
--- a/dtool/src/dtoolbase/mutexImpl.h
+++ b/dtool/src/dtoolbase/mutexImpl.h
@@ -52,9 +52,11 @@ typedef ReMutexPosixImpl ReMutexImpl;
 // interface with an external program or something that wants real
 // locks.
 #if defined(WIN32_VC)
+#include "mutexWin32Impl.h"
 typedef MutexWin32Impl TrueMutexImpl;
 
 #elif defined(HAVE_POSIX_THREADS)
+#include "mutexPosixImpl.h"
 typedef MutexPosixImpl TrueMutexImpl;
 
 #else
diff --git a/dtool/src/dtoolbase/mutexPosixImpl.I b/dtool/src/dtoolbase/mutexPosixImpl.I
index 4ed6054750..e35402a2c3 100644
--- a/dtool/src/dtoolbase/mutexPosixImpl.I
+++ b/dtool/src/dtoolbase/mutexPosixImpl.I
@@ -85,7 +85,7 @@ release() {
 ////////////////////////////////////////////////////////////////////
 INLINE pthread_mutex_t *MutexPosixImpl::
 get_posix_lock() {
-  return _lock;
+  return &_lock;
 }
 
 ////////////////////////////////////////////////////////////////////
@@ -160,5 +160,5 @@ release() {
 ////////////////////////////////////////////////////////////////////
 INLINE pthread_mutex_t *ReMutexPosixImpl::
 get_posix_lock() {
-  return _lock;
+  return &_lock;
 }