diff --git a/c/clang/clang.go b/c/clang/clang.go
index 71bd5a7f..006d3857 100644
--- a/c/clang/clang.go
+++ b/c/clang/clang.go
@@ -1758,6 +1758,14 @@ func (t *TranslationUnit) Tokenize(ran SourceRange, tokens **Token, numTokens *c
 	t.wrapTokenize(&ran, tokens, numTokens)
 }
 
+//  CINDEX_LINKAGE void clang_disposeTokens(CXTranslationUnit TU, CXToken *Tokens, unsigned NumTokens);
+
+/**
+ * Free the given set of tokens.
+ */
+// llgo:link (*TranslationUnit).DisposeTokens C.clang_disposeTokens
+func (t *TranslationUnit) DisposeTokens(tokens *Token, numTokens c.Uint) {}
+
 /**
  * Determine the spelling of the given token.
  *
diff --git a/chore/_xtool/castdump/castdump.go b/chore/_xtool/castdump/castdump.go
index 5b8ac793..7e8b8cb1 100644
--- a/chore/_xtool/castdump/castdump.go
+++ b/chore/_xtool/castdump/castdump.go
@@ -105,6 +105,8 @@ func printMacro(cursor clang.Cursor, unit *clang.TranslationUnit) {
 	var numTokens c.Uint
 	var tokens *clang.Token
 	unit.Tokenize(ran, &tokens, &numTokens)
+	defer unit.DisposeTokens(tokens, numTokens)
+
 	tokensSlice := unsafe.Slice(tokens, int(numTokens))
 	for _, tok := range tokensSlice {
 		tokStr := unit.Token(tok)