diff --git a/clang/lib/CodeGen/CodeGenTBAA.cpp b/clang/lib/CodeGen/CodeGenTBAA.cpp
index 4bcb541156bd2..6eed8e1d2b671 100644
--- a/clang/lib/CodeGen/CodeGenTBAA.cpp
+++ b/clang/lib/CodeGen/CodeGenTBAA.cpp
@@ -246,7 +246,22 @@ llvm::MDNode *CodeGenTBAA::getTypeInfoHelper(const Type *Ty) {
       // Be conservative if the type isn't a RecordType. We are specifically
       // required to do this for member pointers until we implement the
       // similar-types rule.
-      if (!Ty->isRecordType())
+      const auto *RT = Ty->getAs<RecordType>();
+      if (!RT)
+        return AnyPtr;
+
+      // For unnamed structs or unions C's compatible types rule applies. Two
+      // compatible types in different compilation units can have different
+      // mangled names, meaning the metadata emitted below would incorrectly
+      // mark them as no-alias. Use AnyPtr for such types in both C and C++, as
+      // C and C++ types may be visible when doing LTO.
+      //
+      // Note that using AnyPtr is overly conservative. We could summarize the
+      // members of the type, as per the C compatibility rule in the future.
+      // This also covers anonymous structs and unions, which have a different
+      // compatibility rule, but it doesn't matter because you can never have a
+      // pointer to an anonymous struct or union.
+      if (!RT->getDecl()->getDeclName())
         return AnyPtr;
 
       // For non-builtin types use the mangled name of the canonical type.
diff --git a/clang/test/CodeGen/tbaa-pointers.c b/clang/test/CodeGen/tbaa-pointers.c
index 9417a0e2f09e8..068459f4dce11 100644
--- a/clang/test/CodeGen/tbaa-pointers.c
+++ b/clang/test/CodeGen/tbaa-pointers.c
@@ -190,8 +190,6 @@ typedef struct {
   int i1;
 } TypedefS;
 
-// FIXME: The !tbaa tag for unnamed structs doesn't account for compatible
-// types in C.
 void unamed_struct_typedef(TypedefS *ptr) {
 // COMMON-LABEL: define void @unamed_struct_typedef(
 // COMMON-SAME: ptr noundef [[PTRA:%.+]])
@@ -238,5 +236,4 @@ void unamed_struct_typedef(TypedefS *ptr) {
 // DEFAULT: [[S2_TY]]  = !{!"S2", [[ANY_POINTER]], i64 0}
 // COMMON:  [[INT_TAG]] = !{[[INT_TY:!.+]], [[INT_TY]], i64 0}
 // COMMON:  [[INT_TY]] = !{!"int", [[CHAR]], i64 0}
-// ENABLED: [[P1TYPEDEF]] = !{[[P1TYPEDEF_TY:!.+]],  [[P1TYPEDEF_TY]], i64 0}
-// ENABLED: [[P1TYPEDEF_TY]] = !{!"p1 _ZTS8TypedefS", [[ANY_POINTER]], i64 0}
+// ENABLED: [[P1TYPEDEF]] = !{[[ANY_POINTER]],  [[ANY_POINTER]], i64 0}