diff --git a/clang/lib/AST/MicrosoftMangle.cpp b/clang/lib/AST/MicrosoftMangle.cpp
index f7a456e..7ad8b52 100644
--- a/clang/lib/AST/MicrosoftMangle.cpp
+++ b/clang/lib/AST/MicrosoftMangle.cpp
@@ -868,16 +868,11 @@
       }
 
       if (const DecompositionDecl *DD = dyn_cast<DecompositionDecl>(ND)) {
-        // FIXME: Invented mangling for decomposition declarations:
-        //   [X,Y,Z]
-        // where X,Y,Z are the names of the bindings.
-        llvm::SmallString<128> Name("[");
-        for (auto *BD : DD->bindings()) {
-          if (Name.size() > 1)
-            Name += ',';
-          Name += BD->getDeclName().getAsIdentifierInfo()->getName();
-        }
-        Name += ']';
+        // Decomposition declarations are considered anonymous, and get
+        // numbered with a $S prefix.
+        llvm::SmallString<64> Name("$S");
+        // Get a unique id for the anonymous struct.
+        Name += llvm::utostr(Context.getAnonymousStructId(DD) + 1);
         mangleSourceName(Name);
         break;
       }