diff --git a/src/HolyProgress.ts b/src/HolyProgress.ts
index dcd7920..fb43c9b 100644
--- a/src/HolyProgress.ts
+++ b/src/HolyProgress.ts
@@ -48,6 +48,12 @@ type HolyProgressProps = {
    * Default: false
    */
   showSpinner?: boolean;
+
+  /**
+   * Specifies the class attribute value.
+   * Default: undefined
+   */
+  className?: string;
 };
 
 type TransformStrategy = 'translate3d' | 'translate' | 'margin';
@@ -78,6 +84,7 @@ export class HolyProgress {
       zIndex: 2147483647,
       boxShadow: undefined,
       showSpinner: false,
+      className: undefined,
     };
 
     this.settings = { ...defaultSettings, ...customSettings };
@@ -320,6 +327,11 @@ export class HolyProgress {
     this.bar.style.transform = 'translate3d(' + percentage + '%,0,0)';
     this.bar.style.boxShadow = this.settings.boxShadow ?? '';
 
+    if (this.settings.className) {
+      this.bar.className = this.settings.className;
+      this.bar.style.removeProperty('background');
+    }
+    
     document.body.appendChild(progress);
 
     return progress;
diff --git a/src/constants.ts b/src/constants.ts
index bce7dac..1e028a7 100644
--- a/src/constants.ts
+++ b/src/constants.ts
@@ -6,4 +6,5 @@ export const DEFAULTS = {
   speed: 200,
   zIndex: 2147483647,
   showSpinner: false,
+  className: undefined,
 };
diff --git a/src/index.tsx b/src/index.tsx
index 66b8607..8ba4aa2 100644
--- a/src/index.tsx
+++ b/src/index.tsx
@@ -52,6 +52,12 @@ export interface HolyLoaderProps {
    * Default: false
    */
   showSpinner?: boolean;
+
+  /**
+   * Specifies the class attribute value.
+   * Default: undefined
+   */
+  className?: string;
 }
 
 /**
@@ -112,6 +118,7 @@ const HolyLoader = ({
   zIndex = DEFAULTS.zIndex,
   boxShadow,
   showSpinner = DEFAULTS.showSpinner,
+  className = DEFAULTS.className,
 }: HolyLoaderProps): null => {
   React.useEffect(() => {
     let holyProgress: HolyProgress;
@@ -189,6 +196,7 @@ const HolyLoader = ({
         zIndex,
         boxShadow,
         showSpinner,
+        className,
       });
 
       document.addEventListener('click', handleClick);