diff --git a/lib/AST/ASTContext.cpp b/lib/AST/ASTContext.cpp
index 153c893..139ea5e 100644
--- a/lib/AST/ASTContext.cpp
+++ b/lib/AST/ASTContext.cpp
@@ -8290,6 +8290,11 @@
       *NotEncodedT = T;
     return;
 
+  case Type::BitInt:
+    if (NotEncodedT)
+      *NotEncodedT = T;
+    return;
+
   // We could see an undeduced auto type here during error recovery.
   // Just ignore it.
   case Type::Auto:
@@ -8297,7 +8302,6 @@
     return;
 
   case Type::Pipe:
-  case Type::BitInt:
 #define ABSTRACT_TYPE(KIND, BASE)
 #define TYPE(KIND, BASE)
 #define DEPENDENT_TYPE(KIND, BASE) \
diff --git a/test/CodeGenObjC/encode-test-bitint.m b/test/CodeGenObjC/encode-test-bitint.m
new file mode 100644
index 0000000..5f58ffe
--- /dev/null
+++ b/test/CodeGenObjC/encode-test-bitint.m
@@ -0,0 +1,21 @@
+// RUN: %clang_cc1 -triple i686-apple-darwin9 -fobjc-runtime=macosx-fragile-10.5 -fblocks -emit-llvm -o /dev/null %s
+
+// Using a _BitInt as a block parameter or return type previously would crash
+// when getting the ObjC encoding for the type. Verify that we no longer crash,
+// but do not verify any particular encoding (one has not yet been determined).
+void foo1(void)
+{
+    __auto_type blk = ^int(unsigned _BitInt(64) len)
+    {
+        return 12;
+    };
+}
+
+void foo2(void)
+{
+    __auto_type blk = ^unsigned _BitInt(64)(int len)
+    {
+        return 12;
+    };
+}
+