diff --git a/clang/lib/Format/TokenAnnotator.cpp b/clang/lib/Format/TokenAnnotator.cpp
index 9dfe1d3e18f4be..6fc3a4d5d18ae3 100644
--- a/clang/lib/Format/TokenAnnotator.cpp
+++ b/clang/lib/Format/TokenAnnotator.cpp
@@ -3242,7 +3242,13 @@ bool TokenAnnotator::spaceRequiredBetween(const AnnotatedLine &Line,
     return false;
   if (Left.is(tok::period) || Right.is(tok::period))
     return false;
-  if (Right.is(tok::hash) && Left.is(tok::identifier) && Left.TokenText == "L")
+  // u#str, U#str, L#str, u8#str
+  // uR#str, UR#str, LR#str, u8R#str
+  if (Right.is(tok::hash) && Left.is(tok::identifier) &&
+      (Left.TokenText == "L" || Left.TokenText == "u" ||
+       Left.TokenText == "U" || Left.TokenText == "u8" ||
+       Left.TokenText == "LR" || Left.TokenText == "uR" ||
+       Left.TokenText == "UR" || Left.TokenText == "u8R"))
     return false;
   if (Left.is(TT_TemplateCloser) && Left.MatchingParen &&
       Left.MatchingParen->Previous &&
diff --git a/clang/unittests/Format/FormatTest.cpp b/clang/unittests/Format/FormatTest.cpp
index 2eb10609646a65..2b9a72e3741447 100644
--- a/clang/unittests/Format/FormatTest.cpp
+++ b/clang/unittests/Format/FormatTest.cpp
@@ -4396,6 +4396,13 @@ TEST_F(FormatTest, MacroDefinitionInsideStatement) {
 
 TEST_F(FormatTest, HashInMacroDefinition) {
   EXPECT_EQ("#define A(c) L#c", format("#define A(c) L#c", getLLVMStyle()));
+  EXPECT_EQ("#define A(c) u#c", format("#define A(c) u#c", getLLVMStyle()));
+  EXPECT_EQ("#define A(c) U#c", format("#define A(c) U#c", getLLVMStyle()));
+  EXPECT_EQ("#define A(c) u8#c", format("#define A(c) u8#c", getLLVMStyle()));
+  EXPECT_EQ("#define A(c) LR#c", format("#define A(c) LR#c", getLLVMStyle()));
+  EXPECT_EQ("#define A(c) uR#c", format("#define A(c) uR#c", getLLVMStyle()));
+  EXPECT_EQ("#define A(c) UR#c", format("#define A(c) UR#c", getLLVMStyle()));
+  EXPECT_EQ("#define A(c) u8R#c", format("#define A(c) u8R#c", getLLVMStyle()));
   verifyFormat("#define A \\\n  b #c;", getLLVMStyleWithColumns(11));
   verifyFormat("#define A  \\\n"
                "  {        \\\n"