diff --git a/src/LoggerClient.ts b/src/LoggerClient.ts
index e2a6992..c0ba04f 100644
--- a/src/LoggerClient.ts
+++ b/src/LoggerClient.ts
@@ -45,9 +45,9 @@ class LoggerClient implements Logger
             if (typeof this.#_logLevelMapping[type] === 'undefined')
                 throw new Error(`Missing logLevelMapping for type ${type}`);
             Object.defineProperty(this, type, {
-                value: (msg: string, o: WriteOptions) => 
+                value: (msg: string, o?: WriteOptions) => 
                 {
-                    const { labels = [], ...writeOpts } = o;
+                    const { labels = [], ...writeOpts } = o ?? {};
                     this.#transport(msg, { ...writeOpts, type, labels: [ ...this.#labels, ...labels ] });
                 }
             });
diff --git a/src/MasterLogger.ts b/src/MasterLogger.ts
index c2a998c..24f44c1 100644
--- a/src/MasterLogger.ts
+++ b/src/MasterLogger.ts
@@ -85,7 +85,7 @@ class MasterLogger implements Logger
             if (typeof this.#_logLevelMapping[type] === 'undefined')
                 throw new Error(`Missing logLevelMapping for type ${type}`);
             Object.defineProperty(this, type, {
-                value: (msg: string, opts: WriteOptions) => this.write(type, msg, opts)
+                value: (msg: string, opts?: WriteOptions) => this.write(type, msg, opts)
             });
         }
         this.#colours = { ...Defaults.Colours, ...customColours };