diff --git a/lib/CodeGen/Mangle.cpp b/lib/CodeGen/Mangle.cpp
index 011e469..e1e2f10 100644
--- a/lib/CodeGen/Mangle.cpp
+++ b/lib/CodeGen/Mangle.cpp
@@ -1050,6 +1050,18 @@
   if (Quals.hasConst())
     Out << 'K';
 
+  if (Quals.hasAddressSpace()) {
+    // Extension:
+    //
+    //   <type> ::= U <address-space-number>
+    // 
+    // where <address-space-number> is a source name consisting of 'AS' 
+    // followed by the address space <number>.
+    llvm::SmallString<64> ASString;
+    ASString = "AS" + llvm::utostr_32(Quals.getAddressSpace());
+    Out << 'U' << ASString.size() << ASString;
+  }
+  
   // FIXME: For now, just drop all extension qualifiers on the floor.
 }
 
diff --git a/test/CodeGenCXX/mangle-address-space.cpp b/test/CodeGenCXX/mangle-address-space.cpp
new file mode 100644
index 0000000..fbbcbfa
--- /dev/null
+++ b/test/CodeGenCXX/mangle-address-space.cpp
@@ -0,0 +1,6 @@
+// RUN: %clang_cc1 -emit-llvm -o - %s | FileCheck %s
+
+// CHECK: define void @_Z2f0Pc
+void f0(char *p) { }
+// CHECK: define void @_Z2f0PU3AS1c
+void f0(char __attribute__((address_space(1))) *p) { }