diff --git a/dtool/src/dtoolbase/mutexImpl.h b/dtool/src/dtoolbase/mutexImpl.h
index aa1ee81824..c80c8d4e06 100644
--- a/dtool/src/dtoolbase/mutexImpl.h
+++ b/dtool/src/dtoolbase/mutexImpl.h
@@ -42,12 +42,6 @@ typedef MutexWin32Impl MutexImpl;
 typedef MutexWin32Impl ReMutexImpl;  // Win32 Mutexes are always reentrant.
 #define HAVE_REMUTEXIMPL 1
 
-#elif defined(THREAD_LINUX_IMPL)
-
-#include "mutexLinuxImpl.h"
-typedef MutexLinuxImpl MutexImpl;
-#undef HAVE_REMUTEXIMPL  // The futex implementation is non-reentrant.
-
 #elif defined(THREAD_POSIX_IMPL)
 
 #include "mutexPosixImpl.h"
diff --git a/dtool/src/dtoolbase/typeRegistry.I b/dtool/src/dtoolbase/typeRegistry.I
index ae7a025b94..0eb0b070c8 100644
--- a/dtool/src/dtoolbase/typeRegistry.I
+++ b/dtool/src/dtoolbase/typeRegistry.I
@@ -39,7 +39,7 @@ freshen_derivations() {
 ////////////////////////////////////////////////////////////////////
 INLINE void TypeRegistry::
 init_lock() {
-  if (_lock == (ReMutexImpl *)NULL) {
-    _lock = new ReMutexImpl;
+  if (_lock == (MutexImpl *)NULL) {
+    _lock = new MutexImpl;
   }
 }
diff --git a/dtool/src/dtoolbase/typeRegistry.cxx b/dtool/src/dtoolbase/typeRegistry.cxx
index 4a618377b1..ad274a4e6a 100644
--- a/dtool/src/dtoolbase/typeRegistry.cxx
+++ b/dtool/src/dtoolbase/typeRegistry.cxx
@@ -25,7 +25,7 @@
 
 #include <algorithm>
 
-ReMutexImpl *TypeRegistry::_lock = NULL;
+MutexImpl *TypeRegistry::_lock = NULL;
 TypeRegistry *TypeRegistry::_global_pointer = NULL;
 
 ////////////////////////////////////////////////////////////////////
@@ -524,17 +524,7 @@ reregister_types() {
 void TypeRegistry::
 write(ostream &out) const {
   _lock->lock();
-  // Recursively write out the tree, starting from each node that has
-  // no parent.
-  HandleRegistry::const_iterator hi;
-  for (hi = _handle_registry.begin();
-       hi != _handle_registry.end();
-       ++hi) {
-    const TypeRegistryNode *root = *hi;
-    if (root != NULL && root->_parent_classes.empty()) {
-      write_node(out, 2, root);
-    }
-  }
+  do_write(out);
   _lock->release();
 }
 
@@ -632,11 +622,32 @@ rebuild_derivations() {
   }
 }
 
+////////////////////////////////////////////////////////////////////
+//     Function: TypeRegistry::do_write
+//       Access: Private
+//  Description: The private implementation of write(), this assumes
+//               the lock is already held.
+////////////////////////////////////////////////////////////////////
+void TypeRegistry::
+do_write(ostream &out) const {
+  // Recursively write out the tree, starting from each node that has
+  // no parent.
+  HandleRegistry::const_iterator hi;
+  for (hi = _handle_registry.begin();
+       hi != _handle_registry.end();
+       ++hi) {
+    const TypeRegistryNode *root = *hi;
+    if (root != NULL && root->_parent_classes.empty()) {
+      write_node(out, 2, root);
+    }
+  }
+}
+
 ////////////////////////////////////////////////////////////////////
 //     Function: TypeRegistry::write_node
 //       Access: Private
 //  Description: Writes a single TypeRegistryNode out, along with all of
-//               its descendants.
+//               its descendants.  Assumes the lock is already held.
 ////////////////////////////////////////////////////////////////////
 void TypeRegistry::
 write_node(ostream &out, int indent_level, const TypeRegistryNode *node) const {
@@ -666,6 +677,8 @@ write_node(ostream &out, int indent_level, const TypeRegistryNode *node) const {
 //               the object that owns the handle, if available.  It is
 //               only used in an error condition, if for some reason
 //               the handle was uninitialized.
+//
+//               Assumes the lock is already held.
 ////////////////////////////////////////////////////////////////////
 TypeRegistryNode *TypeRegistry::
 look_up(TypeHandle handle, TypedObject *object) const {
@@ -675,8 +688,11 @@ look_up(TypeHandle handle, TypedObject *object) const {
 
     if (object != NULL) {
       // But we're lucky enough to have a TypedObject pointer handy!
-      // Maybe we can use it to resolve the error.
+      // Maybe we can use it to resolve the error.  We have to drop
+      // the lock while we do this, so we don't get a recursive lock.
+      _lock->release();
       handle = object->force_init_type();
+      _lock->lock();
       if (handle._index == 0) {
         // Strange.
         cerr
diff --git a/dtool/src/dtoolbase/typeRegistry.h b/dtool/src/dtoolbase/typeRegistry.h
index 2332c91723..185e40115e 100644
--- a/dtool/src/dtoolbase/typeRegistry.h
+++ b/dtool/src/dtoolbase/typeRegistry.h
@@ -95,6 +95,8 @@ private:
 
   INLINE void freshen_derivations();
   void rebuild_derivations();
+
+  void do_write(ostream &out) const;
   void write_node(ostream &out, int indent_level,
                   const TypeRegistryNode *node) const;
 
@@ -111,7 +113,7 @@ private:
 
   bool _derivations_fresh;
 
-  static ReMutexImpl *_lock;
+  static MutexImpl *_lock;
   static TypeRegistry *_global_pointer;
 
   friend class TypeHandle;
diff --git a/dtool/src/parser-inc/windows.h b/dtool/src/parser-inc/windows.h
index 49d955f8cc..7e9830209d 100644
--- a/dtool/src/parser-inc/windows.h
+++ b/dtool/src/parser-inc/windows.h
@@ -26,6 +26,7 @@
 
 typedef bool BOOL;
 typedef long DWORD;
+typedef long LONG;
 typedef unsigned long ULONG;
 typedef long HRESULT;
 typedef int CRITICAL_SECTION;
diff --git a/panda/src/pipeline/mutexTrueImpl.h b/panda/src/pipeline/mutexTrueImpl.h
index a2197d1bc3..122b598a78 100644
--- a/panda/src/pipeline/mutexTrueImpl.h
+++ b/panda/src/pipeline/mutexTrueImpl.h
@@ -47,7 +47,9 @@ typedef ReMutexSimpleImpl ReMutexTrueImpl;
 #else
 
 typedef MutexImpl MutexTrueImpl;
+#if HAVE_REMUTEXIMPL
 typedef ReMutexImpl ReMutexTrueImpl;
+#endif // HAVE_REMUTEXIMPL
 
 #endif