diff --git a/lib/VMCore/Verifier.cpp b/lib/VMCore/Verifier.cpp
index 3ca9d8c8210..f8dd24c3af6 100644
--- a/lib/VMCore/Verifier.cpp
+++ b/lib/VMCore/Verifier.cpp
@@ -1347,8 +1347,10 @@ void Verifier::visitIntrinsicFunctionCall(Intrinsic::ID ID, CallInst &CI) {
   case Intrinsic::gcwrite:
   case Intrinsic::gcread:
     if (ID == Intrinsic::gcroot) {
-      Assert1(isa<AllocaInst>(CI.getOperand(1)->stripPointerCasts()),
-              "llvm.gcroot parameter #1 must be an alloca.", &CI);
+      AllocaInst *AI =
+        dyn_cast<AllocaInst>(CI.getOperand(1)->stripPointerCasts());
+      Assert1(AI && isa<PointerType>(AI->getType()->getElementType()),
+              "llvm.gcroot parameter #1 must be a pointer alloca.", &CI);
       Assert1(isa<Constant>(CI.getOperand(2)),
               "llvm.gcroot parameter #2 must be a constant.", &CI);
     }
diff --git a/test/CodeGen/Generic/GC/fat.ll b/test/CodeGen/Generic/GC/fat.ll
new file mode 100644
index 00000000000..d05ca3da819
--- /dev/null
+++ b/test/CodeGen/Generic/GC/fat.ll
@@ -0,0 +1,10 @@
+; RUN: not llvm-as < %s >& /dev/null
+
+declare void @llvm.gcroot(i8**, i8*) nounwind
+
+define void @f() gc "x" {
+	%st = alloca { i8*, i1 }		; <{ i8*, i1 }*> [#uses=1]
+	%st_ptr = bitcast { i8*, i1 }* %st to i8**		; <i8**> [#uses=1]
+	call void @llvm.gcroot(i8** %st_ptr, i8* null)
+	ret void
+}