diff --git a/ext/js/core.js b/ext/js/core.js
index 16d81b67..c43d7828 100644
--- a/ext/js/core.js
+++ b/ext/js/core.js
@@ -23,12 +23,15 @@
 function serializeError(error) {
     try {
         if (typeof error === 'object' && error !== null) {
-            return {
+            const result = {
                 name: error.name,
                 message: error.message,
-                stack: error.stack,
-                data: error.data
+                stack: error.stack
             };
+            if (Object.prototype.hasOwnProperty.call(error, 'data')) {
+                result.data = error.data;
+            }
+            return result;
         }
     } catch (e) {
         // NOP
@@ -51,7 +54,9 @@ function deserializeError(serializedError) {
     const error = new Error(serializedError.message);
     error.name = serializedError.name;
     error.stack = serializedError.stack;
-    error.data = serializedError.data;
+    if (Object.prototype.hasOwnProperty.call(serializedError, 'data')) {
+        error.data = serializedError.data;
+    }
     return error;
 }
 
diff --git a/ext/js/templates/sandbox/template-renderer-frame-api.js b/ext/js/templates/sandbox/template-renderer-frame-api.js
index f234c8e0..af83425b 100644
--- a/ext/js/templates/sandbox/template-renderer-frame-api.js
+++ b/ext/js/templates/sandbox/template-renderer-frame-api.js
@@ -72,12 +72,15 @@ class TemplateRendererFrameApi {
     _serializeError(error) {
         try {
             if (typeof error === 'object' && error !== null) {
-                return {
+                const result = {
                     name: error.name,
                     message: error.message,
-                    stack: error.stack,
-                    data: error.data
+                    stack: error.stack
                 };
+                if (Object.prototype.hasOwnProperty.call(error, 'data')) {
+                    result.data = error.data;
+                }
+                return result;
             }
         } catch (e) {
             // NOP
diff --git a/test/test-anki-note-builder.js b/test/test-anki-note-builder.js
index 45087134..2e4beb21 100644
--- a/test/test-anki-note-builder.js
+++ b/test/test-anki-note-builder.js
@@ -92,12 +92,15 @@ async function createVM() {
         _serializeError(error) {
             try {
                 if (typeof error === 'object' && error !== null) {
-                    return {
+                    const result = {
                         name: error.name,
                         message: error.message,
-                        stack: error.stack,
-                        data: error.data
+                        stack: error.stack
                     };
+                    if (Object.prototype.hasOwnProperty.call(error, 'data')) {
+                        result.data = error.data;
+                    }
+                    return result;
                 }
             } catch (e) {
                 // NOP