diff --git a/package.json b/package.json
index 8c26a33..937c22b 100644
--- a/package.json
+++ b/package.json
@@ -1,6 +1,6 @@
 {
   "name": "mfr",
-  "version": "1.1.1",
+  "version": "1.1.2",
   "main": "dist/index.js",
   "files": [
     "/dist"
diff --git a/src/drivers/Driver.ts b/src/drivers/Driver.ts
index 266f159..fb67f88 100644
--- a/src/drivers/Driver.ts
+++ b/src/drivers/Driver.ts
@@ -52,7 +52,7 @@ export abstract class Driver implements IDriver {
 			return '';
 		}
 
-		return typeof prefixPattern === 'function' ? prefixPattern() : prefixPattern!;
+		return typeof prefixPattern === 'function' ? prefixPattern() : prefixPattern ?? '';
 	}
 
 	protected _getPostfix(): string {
@@ -62,6 +62,6 @@ export abstract class Driver implements IDriver {
 			return '';
 		}
 
-		return typeof postfixPattern === 'function' ? postfixPattern() : postfixPattern!;
+		return typeof postfixPattern === 'function' ? postfixPattern() : postfixPattern ?? '';
 	}
 }