diff --git a/lib/Sema/SemaAccess.cpp b/lib/Sema/SemaAccess.cpp
index 69fd543..9bb8f61 100644
--- a/lib/Sema/SemaAccess.cpp
+++ b/lib/Sema/SemaAccess.cpp
@@ -265,6 +265,9 @@
   SmallVector<const CXXRecordDecl*, 8> Queue; // actually a stack
 
   while (true) {
+    if (Derived->isDependentContext() && !Derived->hasDefinition())
+      return AR_dependent;
+    
     for (CXXRecordDecl::base_class_const_iterator
            I = Derived->bases_begin(), E = Derived->bases_end(); I != E; ++I) {
 
diff --git a/test/SemaTemplate/crash-10438657.cpp b/test/SemaTemplate/crash-10438657.cpp
new file mode 100644
index 0000000..2ee64bd
--- /dev/null
+++ b/test/SemaTemplate/crash-10438657.cpp
@@ -0,0 +1,15 @@
+// RUN: not %clang_cc1 -fsyntax-only %s 2> %t
+// RUN: FileCheck %s < %t
+// CHECK: 10 errors
+template<typename _CharT>
+class collate : public locale::facet {
+
+protected:
+virtual ~collate() {}
+  class wxObject;
+  class __attribute__ ((visibility("default"))) wxGDIRefData 
+    : public wxObjectRefData {};
+  class __attribute__ ((visibility("default"))) wxGDIObject : public wxObject { \
+      public:
+      virtual bool IsOk() const {
+        return m_refData && static_cast<wxGDIRefData *>(m_refData)->IsOk();