diff --git a/src/FieldsArray.ts b/src/FieldsArray.ts
index 00e07b0..c4c635c 100644
--- a/src/FieldsArray.ts
+++ b/src/FieldsArray.ts
@@ -92,7 +92,11 @@ function registerWithValidation(
 			instance[sharedKeysPoolSymbol].add(field.key);
 			validItems.push(field);
 		} catch (err) {
-			console.warn(err.message ? err.message : err);
+			if (err instanceof Error) {
+				console.warn(err.message ? err.message : err);
+			} else {
+				console.warn(err);
+			}
 		}
 	}
 
diff --git a/tsconfig.dist.json b/tsconfig.dist.json
index 0599bac..4eef787 100644
--- a/tsconfig.dist.json
+++ b/tsconfig.dist.json
@@ -5,7 +5,5 @@
 		"declaration": true,
 		"sourceMap": true
 	},
-	"include": [
-		"src/**/*",
-	]
+	"include": ["src/**/*"]
 }
diff --git a/tsconfig.json b/tsconfig.json
index d86117c..9f93894 100644
--- a/tsconfig.json
+++ b/tsconfig.json
@@ -4,7 +4,8 @@
 		"target": "es2018",
 		"esModuleInterop": true,
 		"newLine": "LF",
-		"importHelpers": true
+		"importHelpers": true,
+		"useUnknownInCatchVariables": true
 	},
 	"exclude": ["node_modules/"]
 }