diff --git a/src/js/textmode.js b/src/js/textmode.js
index 2e09695..6a9b061 100644
--- a/src/js/textmode.js
+++ b/src/js/textmode.js
@@ -403,12 +403,13 @@ textmode.validate = function () {
 
   // only validate the JSON when parsing the JSON succeeded
   if (doValidate && this.validateSchema) {
-    //console.time('validate'); // TODO: clean up time measurement
     var valid = this.validateSchema(json);
-    //console.timeEnd('validate');
-
     if (!valid) {
-      errors = this.validateSchema.errors;
+      var schema = this.options.schema;
+      errors = this.validateSchema.errors
+          .map(function (error) {
+            return util.improveSchemaError(schema, error);
+          });
     }
   }
 
diff --git a/src/js/treemode.js b/src/js/treemode.js
index dc2e28d..2c6e221 100644
--- a/src/js/treemode.js
+++ b/src/js/treemode.js
@@ -374,10 +374,13 @@ treemode.validate = function () {
 
       // apply all new errors
       schemaErrors = this.validateSchema.errors
+          .map(function (error) {
+            return util.improveSchemaError(schema, error);
+          })
           .map(function findNode (error) {
             return {
               node: root.findNode(error.dataPath),
-              error: improveErrorMessages(error)
+              error: error
             }
           })
           .filter(function hasNode (entry) {
@@ -414,29 +417,6 @@ treemode.validate = function () {
       });
 };
 
-/**
- * Improve the error messages of JSON schema errors
- * @param {Object} error
- * @return {Object} The error
- */
-function improveErrorMessages (error) {
-  if (error.keyword === 'enum') {
-    var enums = util.getFromSchema(schema, error.schemaPath);
-    if (enums) {
-      enums = enums.map(function (value) {
-        return JSON.stringify(value);
-      });
-
-      if (enums.length > 5) {
-        enums = enums.slice(0, 5).concat(['(' + (enums.length - 5) + ' more...)']);
-      }
-      error.message = 'should be equal to one of: ' + enums.join(', ');
-    }
-  }
-
-  return error;
-}
-
 /**
  * Start autoscrolling when given mouse position is above the top of the
  * editor contents, or below the bottom.
diff --git a/src/js/util.js b/src/js/util.js
index 738ca26..a762cd1 100644
--- a/src/js/util.js
+++ b/src/js/util.js
@@ -679,6 +679,32 @@ exports.getFromSchema = function (schema, schemaPath) {
   return obj;
 };
 
+/**
+ * Improve the error message of a JSON schema error
+ * @param {Object} schema
+ * @param {Object} error
+ * @return {Object} The error
+ */
+exports.improveSchemaError = function (schema, error) {
+  if (error.keyword === 'enum') {
+    var enums = exports.getFromSchema(schema, error.schemaPath);
+    if (enums) {
+      enums = enums.map(function (value) {
+        return JSON.stringify(value);
+      });
+
+      if (enums.length > 5) {
+        var more = ['(' + (enums.length - 5) + ' more...)'];
+        enums = enums.slice(0, 5);
+        enums.push(more);
+      }
+      error.message = 'should be equal to one of: ' + enums.join(', ');
+    }
+  }
+
+  return error;
+};
+
 /**
  * Test whether the child rect fits completely inside the parent rect.
  * @param {ClientRect} parent