diff --git a/lib/compile/errors.ts b/lib/compile/errors.ts
index 18d61e917..86565bf8a 100644
--- a/lib/compile/errors.ts
+++ b/lib/compile/errors.ts
@@ -118,11 +118,11 @@ function errorObjectCode(cxt: KeywordErrorCxt, error: KeywordErrorDefinition): C
     [E.keyword, keyword],
     [N.dataPath, strConcat(N.dataPath, errorPath)],
     [E.schemaPath, str`${errSchemaPath}/${keyword}`],
-    [E.params, params ? params(cxt) : _`{}`],
+    [E.params, typeof params == "function" ? params(cxt) : params || _`{}`],
   ]
   if (propertyName) keyValues.push([E.propertyName, propertyName])
   if (opts.messages !== false) {
-    const msg = typeof message == "string" ? message : message(cxt)
+    const msg = typeof message == "function" ? message(cxt) : message
     keyValues.push([E.message, msg])
   }
   if (opts.verbose) {
diff --git a/lib/types/index.ts b/lib/types/index.ts
index fdf181a1a..ec15e8677 100644
--- a/lib/types/index.ts
+++ b/lib/types/index.ts
@@ -159,8 +159,8 @@ export type AddedKeywordDefinition = KeywordDefinition & {
 }
 
 export interface KeywordErrorDefinition {
-  message: string | ((cxt: KeywordErrorCxt) => Code)
-  params?: (cxt: KeywordErrorCxt) => Code
+  message: string | Code | ((cxt: KeywordErrorCxt) => Code)
+  params?: Code | ((cxt: KeywordErrorCxt) => Code)
 }
 
 export type Vocabulary = (KeywordDefinition | string)[]