diff --git a/.changeset/flat-camels-hide.md b/.changeset/flat-camels-hide.md
new file mode 100644
index 0000000000..f902a161e9
--- /dev/null
+++ b/.changeset/flat-camels-hide.md
@@ -0,0 +1,5 @@
+---
+"@marko/compiler": patch
+---
+
+fix sourcemaps
diff --git a/packages/compiler/src/babel-plugin/parser.js b/packages/compiler/src/babel-plugin/parser.js
index 575bd25c08..206e4e6d2c 100644
--- a/packages/compiler/src/babel-plugin/parser.js
+++ b/packages/compiler/src/babel-plugin/parser.js
@@ -203,16 +203,16 @@ export function parseMarko(file) {
       currentTag.node.typeArguments = parseTypeArgs(
         file,
         parser.read(part.value),
-        part.start,
-        part.end
+        part.value.start,
+        part.value.end
       );
     },
     onTagTypeParams(part) {
       currentBody.node.typeParameters = parseTypeParams(
         file,
         parser.read(part.value),
-        part.start,
-        part.end
+        part.value.start,
+        part.value.end
       );
     },
     onPlaceholder(part) {