diff --git a/js&css/web-accessible/www.youtube.com/themes.js b/js&css/web-accessible/www.youtube.com/themes.js
index 5edcd49d3..b47884788 100644
--- a/js&css/web-accessible/www.youtube.com/themes.js
+++ b/js&css/web-accessible/www.youtube.com/themes.js
@@ -75,7 +75,9 @@ ImprovedTube.myColors = function () {
 					document.getElementById("cinematics").style.visibility = 'hidden';
 					document.getElementById("cinematics").style.display = 'none !important';
 				} 
-				document.querySelector('ytd-masthead').style.backgroundColor = ''+primary_color+'';	
+				if (document.querySelector('ytd-masthead')) {
+					document.querySelector('ytd-masthead').style.backgroundColor = ''+primary_color+'';
+				}
 			} else { //theoretically this will never be called 
 				this.elements.my_colors?.remove();
 			}
@@ -94,7 +96,9 @@ let darkCookie;
 				document.getElementById('cinematics').style.display = 'none !important';
 			}
 			this.elements.my_colors?.remove();
-			document.querySelector('ytd-masthead').style.backgroundColor ='#000';
+			if (document.querySelector('ytd-masthead')) {
+				document.querySelector('ytd-masthead').style.backgroundColor ='#000';
+			}
 			break
 
 		case 'default':