diff --git a/llvm/lib/Transforms/IPO/LowerTypeTests.cpp b/llvm/lib/Transforms/IPO/LowerTypeTests.cpp
index d855647095550..d615c10c23030 100644
--- a/llvm/lib/Transforms/IPO/LowerTypeTests.cpp
+++ b/llvm/lib/Transforms/IPO/LowerTypeTests.cpp
@@ -1715,8 +1715,22 @@ void LowerTypeTestsModule::buildBitSetsFromFunctionsNative(
           F->getValueType(), 0, F->getLinkage(), "", CombinedGlobalElemPtr, &M);
       FAlias->setVisibility(F->getVisibility());
       FAlias->takeName(F);
-      if (FAlias->hasName())
+      if (FAlias->hasName()) {
         F->setName(FAlias->getName() + ".cfi");
+        // For COFF we should also rename the comdat if this function also
+        // happens to be the key function. Even if the comdat name changes, this
+        // should still be fine since comdat and symbol resolution happens
+        // before LTO, so all symbols which would prevail have been selected.
+        if (F->hasComdat() && ObjectFormat == Triple::COFF &&
+            F->getComdat()->getName() == FAlias->getName()) {
+          Comdat *OldComdat = F->getComdat();
+          Comdat *NewComdat = M.getOrInsertComdat(F->getName());
+          for (GlobalObject &GO : M.global_objects()) {
+            if (GO.getComdat() == OldComdat)
+              GO.setComdat(NewComdat);
+          }
+        }
+      }
       replaceCfiUses(F, FAlias, IsJumpTableCanonical);
       if (!F->hasLocalLinkage())
         F->setVisibility(GlobalVariable::HiddenVisibility);
diff --git a/llvm/test/Transforms/LowerTypeTests/cfi-coff-comdat-rename.ll b/llvm/test/Transforms/LowerTypeTests/cfi-coff-comdat-rename.ll
new file mode 100644
index 0000000000000..aa56a3abf00fc
--- /dev/null
+++ b/llvm/test/Transforms/LowerTypeTests/cfi-coff-comdat-rename.ll
@@ -0,0 +1,35 @@
+; RUN: opt -S -passes=lowertypetests %s | FileCheck %s
+
+;; This is a check to assert we don't crash with:
+;;
+;;   LLVM ERROR: Associative COMDAT symbol '...' does not exist.
+;;
+;; So this just needs to exit normally.
+; RUN: opt -S -passes=lowertypetests %s | llc -asm-verbose=false
+
+target datalayout = "e-p:64:64"
+target triple = "x86_64-pc-windows-msvc"
+
+@a = global [2 x ptr] [ptr @f1, ptr @f2]
+
+; CHECK: $f1.cfi = comdat any
+$f1 = comdat any
+
+; CHECK: @f1.cfi() comdat !type !0
+define void @f1() comdat !type !0 {
+  ret void
+}
+
+; CHECK: @f2.cfi() comdat($f1.cfi) !type !0
+define void @f2() comdat($f1) !type !0 {
+  ret void
+}
+
+declare i1 @llvm.type.test(ptr %ptr, metadata %bitset) nounwind readnone
+
+define i1 @foo(ptr %p) {
+  %x = call i1 @llvm.type.test(ptr %p, metadata !"typeid1")
+  ret i1 %x
+}
+
+!0 = !{i32 0, !"typeid1"}