diff --git a/llvm/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp b/llvm/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp
index 94cb9580..f1e879b 100644
--- a/llvm/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp
+++ b/llvm/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp
@@ -5050,7 +5050,7 @@
   }
   case Intrinsic::gcroot:
     if (GFI) {
-      const Value *Alloca = I.getArgOperand(0);
+      const Value *Alloca = I.getArgOperand(0)->stripPointerCasts();
       const Constant *TypeMap = cast<Constant>(I.getArgOperand(1));
 
       FrameIndexSDNode *FI = cast<FrameIndexSDNode>(getValue(Alloca).getNode());
diff --git a/llvm/test/CodeGen/X86/GC/cg-O0.ll b/llvm/test/CodeGen/X86/GC/cg-O0.ll
new file mode 100644
index 0000000..b492942
--- /dev/null
+++ b/llvm/test/CodeGen/X86/GC/cg-O0.ll
@@ -0,0 +1,17 @@
+; RUN: llc < %s -O0
+
+define i32 @main() {
+entry:
+  call void @f()
+  ret i32 0
+}
+
+define void @f() gc "ocaml" {
+entry:
+  %ptr.stackref = alloca i8*
+  %gcroot = bitcast i8** %ptr.stackref to i8**
+  call void @llvm.gcroot(i8** %gcroot, i8* null)
+  ret void
+}
+
+declare void @llvm.gcroot(i8**, i8*) nounwind