diff --git a/clang-tools-extra/pseudo/lib/cxx/CXX.cpp b/clang-tools-extra/pseudo/lib/cxx/CXX.cpp
index e8de6821a05f5..9a03422153f06 100644
--- a/clang-tools-extra/pseudo/lib/cxx/CXX.cpp
+++ b/clang-tools-extra/pseudo/lib/cxx/CXX.cpp
@@ -33,11 +33,26 @@ bool guardFinal(llvm::ArrayRef<const ForestNode *> RHS,
          RHS.front()->symbol() == tokenSymbol(clang::tok::identifier));
   return Tokens.tokens()[RHS.front()->startTokenIndex()].text() == "final";
 }
+bool guardModule(llvm::ArrayRef<const ForestNode *> RHS,
+                 const TokenStream &Tokens) {
+  return Tokens.tokens()[RHS.front()->startTokenIndex()].text() == "module";
+}
+bool guardImport(llvm::ArrayRef<const ForestNode *> RHS,
+                 const TokenStream &Tokens) {
+  return Tokens.tokens()[RHS.front()->startTokenIndex()].text() == "import";
+}
+bool guardExport(llvm::ArrayRef<const ForestNode *> RHS,
+                 const TokenStream &Tokens) {
+  return Tokens.tokens()[RHS.front()->startTokenIndex()].text() == "export";
+}
 
 llvm::DenseMap<ExtensionID, RuleGuard> buildGuards() {
   return {
       {(ExtensionID)Extension::Override, guardOverride},
       {(ExtensionID)Extension::Final, guardFinal},
+      {(ExtensionID)Extension::Import, guardImport},
+      {(ExtensionID)Extension::Export, guardExport},
+      {(ExtensionID)Extension::Module, guardModule},
   };
 }
 
diff --git a/clang-tools-extra/pseudo/lib/cxx/cxx.bnf b/clang-tools-extra/pseudo/lib/cxx/cxx.bnf
index b80dfd928f2b4..08384af9d9399 100644
--- a/clang-tools-extra/pseudo/lib/cxx/cxx.bnf
+++ b/clang-tools-extra/pseudo/lib/cxx/cxx.bnf
@@ -748,10 +748,10 @@ pointer-literal := NULLPTR
 #! Placeholders for literal text in the grammar that lex as other things.
 contextual-override := IDENTIFIER [guard=Override]
 contextual-final := IDENTIFIER [guard=Final]
-contextual-zero := NUMERIC_CONSTANT
-module-keyword := IDENTIFIER
-import-keyword := IDENTIFIER
-export-keyword := IDENTIFIER
+contextual-zero := NUMERIC_CONSTANT [guard=Zero]
+module-keyword := IDENTIFIER [guard=Module]
+import-keyword := IDENTIFIER [guard=Import]
+export-keyword := IDENTIFIER [guard=Export]
 
 #! greatergreater token -- clang lexer always lexes it as a single token, we
 #! split it into two tokens to make the GLR parser aware of the nested-template