diff --git a/clang/lib/Format/FormatToken.cpp b/clang/lib/Format/FormatToken.cpp
index 33bcde3c25ece..b791c5a26bbe3 100644
--- a/clang/lib/Format/FormatToken.cpp
+++ b/clang/lib/Format/FormatToken.cpp
@@ -14,7 +14,9 @@
 
 #include "FormatToken.h"
 #include "ContinuationIndenter.h"
-#include "TokenAnalyzer.h"
+#include "llvm/ADT/SmallVector.h"
+#include "llvm/Support/Debug.h"
+#include <climits>
 
 namespace clang {
 namespace format {
@@ -32,9 +34,41 @@ const char *getTokenTypeName(TokenType Type) {
   return nullptr;
 }
 
+// FIXME: This is copy&pasted from Sema. Put it in a common place and remove
+// duplication.
 bool FormatToken::isSimpleTypeSpecifier() const {
-  assert(LangOpts.CPlusPlus);
-  return Tok.isSimpleTypeSpecifier(LangOpts);
+  switch (Tok.getKind()) {
+  case tok::kw_short:
+  case tok::kw_long:
+  case tok::kw___int64:
+  case tok::kw___int128:
+  case tok::kw_signed:
+  case tok::kw_unsigned:
+  case tok::kw_void:
+  case tok::kw_char:
+  case tok::kw_int:
+  case tok::kw_half:
+  case tok::kw_float:
+  case tok::kw_double:
+  case tok::kw___bf16:
+  case tok::kw__Float16:
+  case tok::kw___float128:
+  case tok::kw___ibm128:
+  case tok::kw_wchar_t:
+  case tok::kw_bool:
+#define TRANSFORM_TYPE_TRAIT_DEF(_, Trait) case tok::kw___##Trait:
+#include "clang/Basic/TransformTypeTraits.def"
+  case tok::annot_typename:
+  case tok::kw_char8_t:
+  case tok::kw_char16_t:
+  case tok::kw_char32_t:
+  case tok::kw_typeof:
+  case tok::kw_decltype:
+  case tok::kw__Atomic:
+    return true;
+  default:
+    return false;
+  }
 }
 
 bool FormatToken::isTypeOrIdentifier() const {