diff --git a/src/LoggerClient.ts b/src/LoggerClient.ts
index 257ba87..9b0945a 100644
--- a/src/LoggerClient.ts
+++ b/src/LoggerClient.ts
@@ -46,16 +46,19 @@ class LoggerClient implements Logger
 
         const { customTypes = [] } = opts;
         this.#types = [ ...customTypes, ...Defaults.Types ];
-        for (const type of this.#types) 
+        this.#_logLevelMapping = { ...Defaults.ClientOptions.logLevelMapping, ...opts.logLevelMapping };
+        this.#_guard = opts.guard || Defaults.ClientOptions.guard as string;
+        this.#_logLevel = opts.logLevel ?? Defaults.ClientOptions.logLevel as number;
+
+        for (const type of this.#types)
         {
+            if (typeof this.#_logLevelMapping[type] === 'undefined')
+                throw new Error(`Missing logLevelMapping for type ${type}`);
             Object.defineProperty(this, type, {
                 value: (msg: string, o: WriteOptions) => this.#transport(msg, { ...o, type })
             });
         }
 
-        this.#_guard = opts.guard || Defaults.ClientOptions.guard as string;
-        this.#_logLevel = opts.logLevel ?? Defaults.ClientOptions.logLevel as number;
-        this.#_logLevelMapping = { ...Defaults.ClientOptions.logLevelMapping, ...opts.logLevelMapping };
 
     }
 
diff --git a/src/MasterLogger.ts b/src/MasterLogger.ts
index 9f3dba9..a412560 100644
--- a/src/MasterLogger.ts
+++ b/src/MasterLogger.ts
@@ -55,7 +55,6 @@ class MasterLogger implements Logger
 
     constructor (config = Defaults.MasterOptions) 
     {
-
         const {
             directory, customTypes = [], customStreams = [], customTypeMapping,
             customColours, guard, fileRotationFreq, logLevel, logLevelMapping,
@@ -82,6 +81,8 @@ class MasterLogger implements Logger
         this.#types = [ ...customTypes, ...Defaults.Types ];
         for (const type of this.#types) 
         {
+            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)
             });
@@ -206,8 +207,6 @@ class MasterLogger implements Logger
 
     write (type = 'info', text: string | object | Error, { subheader = '', shard, broadcast = false }: WriteOptions = {}) 
     {
-
-        type = type.toLowerCase();
         let colour = this.#colourFuncs[type];
         if (!colour) 
             colour = this.#colourFuncs.info;