diff --git a/package.json b/package.json
index 1ac8acf..e73c13a 100644
--- a/package.json
+++ b/package.json
@@ -35,7 +35,7 @@
   },
   "dependencies": {
     "ajv": "^8.0.0",
-    "fast-json-patch": "^2.0.0",
+    "fast-json-patch": "^3.1.1",
     "glob": "^7.1.0",
     "js-yaml": "^3.14.0",
     "json-schema-migrate": "^2.0.0",
diff --git a/src/commands/ajv.ts b/src/commands/ajv.ts
index d06acb5..b4384b7 100644
--- a/src/commands/ajv.ts
+++ b/src/commands/ajv.ts
@@ -86,9 +86,11 @@ export default function (argv: ParsedArgs): AjvCore {
       registerer = require("ts-node").register()
     } catch (err) {
       /* istanbul ignore next */
-      if (err.code === "MODULE_NOT_FOUND") {
+      if ((err as {code?: string; message: string}).code === "MODULE_NOT_FOUND") {
         throw new Error(
-          `'ts-node' is required for the TypeScript configuration files. Make sure it is installed\nError: ${err.message}`
+          `'ts-node' is required for the TypeScript configuration files. Make sure it is installed\nError: ${
+            (err as Error).message
+          }`
         )
       }
 
diff --git a/src/commands/util.ts b/src/commands/util.ts
index 42b4ed1..c182f01 100644
--- a/src/commands/util.ts
+++ b/src/commands/util.ts
@@ -52,7 +52,7 @@ export function openFile(filename: string, suffix: string): any {
       json = require(file)
     }
   } catch (err) {
-    const msg: string = err.message
+    const msg: string = (err as Error).message
     console.error(`error:  ${msg.replace(" module", " " + suffix)}`)
     process.exit(2)
   }
@@ -82,7 +82,7 @@ export function compile(ajv: Ajv, schemaFile: string): AnyValidateFunction {
     return ajv.compile(schema)
   } catch (err) {
     console.error(`schema ${schemaFile} is invalid`)
-    console.error(`error: ${err.message}`)
+    console.error(`error: ${(err as Error).message}`)
     process.exit(1)
   }
 }