diff --git a/src/parser/compat.ts b/src/parser/compat.ts
index d3a1ce07..4d512b42 100644
--- a/src/parser/compat.ts
+++ b/src/parser/compat.ts
@@ -34,9 +34,17 @@ export function getOptionsFromRoot(
 ): Compiler.SvelteOptionsRaw | null {
   const root = svelteAst as Compiler.Root;
   if (root.options) {
+    // The name "svelte:options" starts after the opening "<"
+    const nameStart = root.options.start + 1;
+    const nameEnd = nameStart + "svelte:options".length;
     return {
       type: "SvelteOptions",
       name: "svelte:options",
+      // name_loc is required in Svelte 5.42+
+      name_loc: {
+        start: { line: 0, column: nameStart },
+        end: { line: 0, column: nameEnd },
+      },
       attributes: root.options.attributes,
       fragment: {
         type: "Fragment",
@@ -44,7 +52,7 @@ export function getOptionsFromRoot(
       },
       start: root.options.start,
       end: root.options.end,
-    };
+    } as Compiler.SvelteOptionsRaw;
   }
   return null;
 }
diff --git a/src/parser/html.ts b/src/parser/html.ts
index 6c713bc8..019f5b79 100644
--- a/src/parser/html.ts
+++ b/src/parser/html.ts
@@ -83,30 +83,36 @@ function parseAttribute(state: State): Compiler.Attribute {
     return {
       type: "Attribute",
       name: key,
+      // name_loc is required in Svelte 5.42+
+      name_loc: null,
       value: true,
       start,
       end: keyEnd,
-    };
+    } as Compiler.Attribute;
   }
   state.skipSpaces();
   if (state.eof()) {
     return {
       type: "Attribute",
       name: key,
+      // name_loc is required in Svelte 5.42+
+      name_loc: null,
       value: true,
       start,
       end: keyEnd,
-    };
+    } as Compiler.Attribute;
   }
   // parse value
   const value = parseAttributeValue(state);
   return {
     type: "Attribute",
     name: key,
+    // name_loc is required in Svelte 5.42+
+    name_loc: null,
     value: [value],
     start,
     end: state.index,
-  };
+  } as Compiler.Attribute;
 }
 
 /** Parse HTML attribute key */
diff --git a/tests/src/parser/__snapshots__/html.ts.snap b/tests/src/parser/__snapshots__/html.ts.snap
index bffe7bf1..54740751 100644
--- a/tests/src/parser/__snapshots__/html.ts.snap
+++ b/tests/src/parser/__snapshots__/html.ts.snap
@@ -13,6 +13,7 @@ Object {
     Object {
       "end": 17,
       "name": "lang",
+      "name_loc": null,
       "start": 8,
       "type": "Attribute",
       "value": Array [
@@ -36,6 +37,7 @@ Object {
     Object {
       "end": 17,
       "name": "lang",
+      "name_loc": null,
       "start": 8,
       "type": "Attribute",
       "value": Array [
@@ -59,6 +61,7 @@ Object {
     Object {
       "end": 15,
       "name": "lang",
+      "name_loc": null,
       "start": 8,
       "type": "Attribute",
       "value": Array [
@@ -82,6 +85,7 @@ Object {
     Object {
       "end": 13,
       "name": "global",
+      "name_loc": null,
       "start": 7,
       "type": "Attribute",
       "value": true,
@@ -97,6 +101,7 @@ Object {
     Object {
       "end": 13,
       "name": "global",
+      "name_loc": null,
       "start": 7,
       "type": "Attribute",
       "value": true,
@@ -112,6 +117,7 @@ Object {
     Object {
       "end": 4,
       "name": "attr",
+      "name_loc": null,
       "start": 0,
       "type": "Attribute",
       "value": true,
@@ -127,6 +133,7 @@ Object {
     Object {
       "end": 4,
       "name": "attr",
+      "name_loc": null,
       "start": 0,
       "type": "Attribute",
       "value": true,
@@ -142,6 +149,7 @@ Object {
     Object {
       "end": 16,
       "name": "attr",
+      "name_loc": null,
       "start": 0,
       "type": "Attribute",
       "value": Array [
@@ -165,6 +173,7 @@ Object {
     Object {
       "end": 12,
       "name": "attr",
+      "name_loc": null,
       "start": 0,
       "type": "Attribute",
       "value": Array [
@@ -188,6 +197,7 @@ Object {
     Object {
       "end": 8,
       "name": "empty",
+      "name_loc": null,
       "start": 0,
       "type": "Attribute",
       "value": Array [
@@ -211,6 +221,7 @@ Object {
     Object {
       "end": 8,
       "name": "empty",
+      "name_loc": null,
       "start": 0,
       "type": "Attribute",
       "value": Array [
@@ -234,6 +245,7 @@ Object {
     Object {
       "end": 13,
       "name": "expr",
+      "name_loc": null,
       "start": 0,
       "type": "Attribute",
       "value": Array [
@@ -263,6 +275,7 @@ Object {
     Object {
       "end": 13,
       "name": "expr",
+      "name_loc": null,
       "start": 0,
       "type": "Attribute",
       "value": Array [
@@ -292,6 +305,7 @@ Object {
     Object {
       "end": 10,
       "name": "expr",
+      "name_loc": null,
       "start": 0,
       "type": "Attribute",
       "value": Array [
@@ -321,6 +335,7 @@ Object {
     Object {
       "end": 10,
       "name": "expr",
+      "name_loc": null,
       "start": 0,
       "type": "Attribute",
       "value": Array [
@@ -350,6 +365,7 @@ Object {
     Object {
       "end": 15,
       "name": "expr",
+      "name_loc": null,
       "start": 0,
       "type": "Attribute",
       "value": Array [
@@ -387,6 +403,7 @@ Object {
     Object {
       "end": 19,
       "name": "expr",
+      "name_loc": null,
       "start": 0,
       "type": "Attribute",
       "value": Array [
@@ -429,6 +446,7 @@ Object {
     Object {
       "end": 11,
       "name": "expr",
+      "name_loc": null,
       "start": 0,
       "type": "Attribute",
       "value": Array [
@@ -458,6 +476,7 @@ Object {
     Object {
       "end": 9,
       "name": "quote",
+      "name_loc": null,
       "start": 0,
       "type": "Attribute",
       "value": Array [
@@ -481,6 +500,7 @@ Object {
     Object {
       "end": 9,
       "name": "quote",
+      "name_loc": null,
       "start": 0,
       "type": "Attribute",
       "value": Array [