diff --git a/clang/lib/Format/TokenAnnotator.cpp b/clang/lib/Format/TokenAnnotator.cpp
--- a/clang/lib/Format/TokenAnnotator.cpp
+++ b/clang/lib/Format/TokenAnnotator.cpp
@@ -1337,11 +1337,11 @@
     if (CurrentToken &&
         CurrentToken->isOneOf(Keywords.kw_mark, Keywords.kw_option,
                               Keywords.kw_region)) {
-      bool IsMark = CurrentToken->is(Keywords.kw_mark);
+      bool IsMarkOrRegion = CurrentToken->isOneOf(Keywords.kw_mark, Keywords.kw_region);
       next();
       next(); // Consume first token (so we fix leading whitespace).
       while (CurrentToken) {
-        if (IsMark || CurrentToken->Previous->is(TT_BinaryOperator))
+        if (IsMarkOrRegion || CurrentToken->Previous->is(TT_BinaryOperator))
           CurrentToken->setType(TT_ImplicitStringLiteral);
         next();
       }
diff --git a/clang/unittests/Format/FormatTest.cpp b/clang/unittests/Format/FormatTest.cpp
--- a/clang/unittests/Format/FormatTest.cpp
+++ b/clang/unittests/Format/FormatTest.cpp
@@ -19965,9 +19965,7 @@
 TEST_F(FormatTest, UnderstandPragmaRegion) {
   auto Style = getLLVMStyleWithColumns(0);
   verifyFormat("#pragma region TEST(FOO : BAR)", Style);
-
-  EXPECT_EQ("#pragma region TEST(FOO : BAR)",
-            format("#pragma region TEST(FOO : BAR)", Style));
+  verifyFormat("#pragma region TEST(FOO: NOSPACE)", Style);
 }
 
 TEST_F(FormatTest, OptimizeBreakPenaltyVsExcess) {
diff --git a/clang/unittests/Format/TokenAnnotatorTest.cpp b/clang/unittests/Format/TokenAnnotatorTest.cpp
--- a/clang/unittests/Format/TokenAnnotatorTest.cpp
+++ b/clang/unittests/Format/TokenAnnotatorTest.cpp
@@ -6,6 +6,7 @@
 //
 //===----------------------------------------------------------------------===//
 
+#include "clang/Basic/TokenKinds.h"
 #include "clang/Format/Format.h"
 
 #include "FormatTestUtils.h"
@@ -649,6 +650,23 @@
   EXPECT_TOKEN(Tokens[14], tok::l_brace, TT_RequiresExpressionLBrace);
 }
 
+TEST_F(TokenAnnotatorTest, UnderstandsPragmaRegion) {
+  // Everything after #pragma region should be ImplicitStringLiteral
+  auto Tokens = annotate("#pragma region Foo(Bar: Hello)");
+  ASSERT_EQ(Tokens.size(), 10u) << Tokens;
+  EXPECT_TOKEN(Tokens[5], tok::identifier, TT_ImplicitStringLiteral);
+  EXPECT_TOKEN(Tokens[6], tok::colon, TT_ImplicitStringLiteral);
+  EXPECT_TOKEN(Tokens[7], tok::identifier, TT_ImplicitStringLiteral);
+
+  // Make sure it's annotated correctly inside a function as well
+  Tokens = annotate("void test(){\n#pragma region Foo(Bar: Hello)\n}");
+  ASSERT_EQ(Tokens.size(), 16u) << Tokens;
+  EXPECT_TOKEN(Tokens[10], tok::identifier, TT_ImplicitStringLiteral);
+  EXPECT_TOKEN(Tokens[11], tok::colon, TT_ImplicitStringLiteral);
+  EXPECT_TOKEN(Tokens[12], tok::identifier, TT_ImplicitStringLiteral);
+
+}
+
 TEST_F(TokenAnnotatorTest, RequiresDoesNotChangeParsingOfTheRest) {
   const char *BaseCode = nullptr;
   const char *ConstrainedCode = nullptr;