diff --git a/ext/home/main.php b/ext/home/main.php
index 548b8ea7..ca00a98d 100644
--- a/ext/home/main.php
+++ b/ext/home/main.php
@@ -70,8 +70,8 @@ class Home extends Extension {
 		}
 		else {
 			$main_links = '[url=site://post/list]Posts[/url] [url=site://comment/list]Comments[/url] [url=site://tags]Tags[/url]';
-			if(file_exists("ext/pools")) {$main_links .= ' [url=site://pools]Pools[/url]';}
-			if(file_exists("ext/wiki")) {$main_links .= ' [url=site://wiki]Wiki[/url]';}
+			if(class_exists("Pools")) {$main_links .= ' [url=site://pools]Pools[/url]';}
+			if(class_exists("Wiki")) {$main_links .= ' [url=site://wiki]Wiki[/url]';}
 			$main_links .= ' [url=site://ext_doc]>>[/url]';
 		}
 		$main_links = format_text($main_links);
diff --git a/ext/image/main.php b/ext/image/main.php
index 29f71dc5..6f72a557 100644
--- a/ext/image/main.php
+++ b/ext/image/main.php
@@ -295,7 +295,7 @@ class ImageIO extends Extension {
 			if($handler == "merge" || isset($_GET['update'])) {
 				$merged = array_merge($image->get_tag_array(), $existing->get_tag_array());
 				send_event(new TagSetEvent($existing, $merged));
-				if(isset($_GET['rating']) && isset($_GET['update']) && file_exists("ext/rating")){
+				if(isset($_GET['rating']) && isset($_GET['update']) && class_exists("Ratings")){
 					send_event(new RatingSetEvent($existing, $user, $_GET['rating']));
 				}
 				if(isset($_GET['source']) && isset($_GET['update'])){
diff --git a/ext/upload/main.php b/ext/upload/main.php
index 06723691..c836f03f 100644
--- a/ext/upload/main.php
+++ b/ext/upload/main.php
@@ -329,7 +329,7 @@ class Upload extends Extension {
 		}
 		
 		// Checks if url contains rating, also checks if the rating extension is enabled.
-		if($config->get_string("transload_engine", "none") != "none" && file_exists("ext/rating") && !empty($_GET['rating'])) {
+		if($config->get_string("transload_engine", "none") != "none" && class_exists("Ratings") && !empty($_GET['rating'])) {
 			// Rating event will validate that this is s/q/e/u
 			$rating = strtolower($_GET['rating']);
 			$rating = $rating[0];
diff --git a/ext/upload/theme.php b/ext/upload/theme.php
index 80494214..8fe5c3fe 100644
--- a/ext/upload/theme.php
+++ b/ext/upload/theme.php
@@ -215,10 +215,10 @@ class UploadTheme extends Themelet {
 
 		// Bookmarklet checks if shimmie supports ext. If not, won't upload to site/shows alert saying not supported.
 		$supported_ext = "jpg jpeg gif png";
-		if(file_exists("ext/handle_flash")){$supported_ext .= " swf";}
-		if(file_exists("ext/handle_ico")){$supported_ext .= " ico ani cur";}
-		if(file_exists("ext/handle_mp3")){$supported_ext .= " mp3";}
-		if(file_exists("ext/handle_svg")){$supported_ext .= " svg";}
+		if(class_exists("FlashFileHandler")){$supported_ext .= " swf";}
+		if(class_exists("ICOFileHandler")){$supported_ext .= " ico ani cur";}
+		if(class_exists("MP3FileHandler")){$supported_ext .= " mp3";}
+		if(class_exists("SVGFileHandler")){$supported_ext .= " svg";}
 		$title = "Booru to " . $config->get_string('title');
 		// CA=0: Ask to use current or new tags | CA=1: Always use current tags | CA=2: Always use new tags
 		$html .= '<p><a href="javascript:
diff --git a/themes/danbooru/layout.class.php b/themes/danbooru/layout.class.php
index 935d1522..bf9763f2 100644
--- a/themes/danbooru/layout.class.php
+++ b/themes/danbooru/layout.class.php
@@ -140,11 +140,11 @@ class Layout {
 				# be nice to be correct
 			case "post":
 			case "upload":
-				if(file_exists("ext/numeric_score")){ $custom_sublinks .= "<li><b>Popular by </b><a href='".make_link('popular_by_day')."'>Day</a>/<a href='".make_link('popular_by_month')."'>Month</a>/<a href='".make_link('popular_by_year')."'>Year</a></li>";}
+				if(class_exists("NumericScore")){ $custom_sublinks .= "<li><b>Popular by </b><a href='".make_link('popular_by_day')."'>Day</a>/<a href='".make_link('popular_by_month')."'>Month</a>/<a href='".make_link('popular_by_year')."'>Year</a></li>";}
 				$custom_sublinks .= "<li><a href='".make_link('post/list')."'>All</a></li>";
-				if(file_exists("ext/favorites")){ $custom_sublinks .= "<li><a href='".make_link("post/list/favorited_by=$username/1")."'>My Favorites</a></li>";}
-				if(file_exists("ext/rss_images")){ $custom_sublinks .= "<li><a href='".make_link('rss/images')."'>Feed</a></li>";}
-				if(file_exists("ext/random_image")){ $custom_sublinks .= "<li><a href='".make_link("random_image/view")."'>Random Image</a></li>";}
+				if(class_exists("Favorites")){ $custom_sublinks .= "<li><a href='".make_link("post/list/favorited_by=$username/1")."'>My Favorites</a></li>";}
+				if(class_exists("RSS_Images")){ $custom_sublinks .= "<li><a href='".make_link('rss/images')."'>Feed</a></li>";}
+				if(class_exists("RandomImage")){ $custom_sublinks .= "<li><a href='".make_link("random_image/view")."'>Random Image</a></li>";}
 				if($hw){ $custom_sublinks .= "<li><a href='".make_link("wiki/posts")."'>Help</a></li>";
 				}else{ $custom_sublinks .= "<li><a href='".make_link("ext_doc/index")."'>Help</a></li>";}
 				break;
diff --git a/themes/danbooru/view.theme.php b/themes/danbooru/view.theme.php
index c5823dbd..d7f0008b 100644
--- a/themes/danbooru/view.theme.php
+++ b/themes/danbooru/view.theme.php
@@ -38,7 +38,7 @@ class CustomViewImageTheme extends ViewImageTheme {
 			$html .= "<br>Source: <a href='$h_source'>link</a>";
 		}
 
-		if(file_exists("ext/rating")) {
+		if(class_exists("Ratings")) {
 			if($image->rating == null || $image->rating == "u"){
 				$image->rating = "u";
 			}
diff --git a/themes/lite/layout.class.php b/themes/lite/layout.class.php
index 14ea1e88..39364bc4 100644
--- a/themes/lite/layout.class.php
+++ b/themes/lite/layout.class.php
@@ -94,11 +94,11 @@ class Layout {
 				# the subnav links aren't shown, but it would
 				# be nice to be correct
 			case "post":
-				if(file_exists("ext/numeric_score")){ $cs .= "<b>Popular by </b><a href='".make_link('popular_by_day')."'>Day</a><b>/</b><a href='".make_link('popular_by_month')."'>Month</a><b>/</b><a href='".make_link('popular_by_year')."'>Year</a> ";}
+				if(class_exists("NumericScore")){ $cs .= "<b>Popular by </b><a href='".make_link('popular_by_day')."'>Day</a><b>/</b><a href='".make_link('popular_by_month')."'>Month</a><b>/</b><a href='".make_link('popular_by_year')."'>Year</a> ";}
 				$cs .= "<a class='tab' href='".make_link('post/list')."'>All</a>";
-				if(file_exists("ext/favorites")){ $cs .= "<a class='tab' href='".make_link("post/list/favorited_by=$username/1")."'>My Favorites</a>";}
-				if(file_exists("ext/rss_images")){ $cs .= "<a class='tab' href='".make_link('rss/images')."'>Feed</a>";}
-				if(file_exists("ext/random_image")){ $cs .= "<a class='tab' href='".make_link("random_image/view")."'>Random Image</a>";}
+				if(class_exists("Favorites")){ $cs .= "<a class='tab' href='".make_link("post/list/favorited_by=$username/1")."'>My Favorites</a>";}
+				if(class_exists("RSS_Images")){ $cs .= "<a class='tab' href='".make_link('rss/images')."'>Feed</a>";}
+				if(class_exists("Random_Image")){ $cs .= "<a class='tab' href='".make_link("random_image/view")."'>Random Image</a>";}
 				if($hw){ $cs .= "<a class='tab' href='".make_link("wiki/posts")."'>Help</a>";
 				}else{ $cs .= "<a class='tab' href='".make_link("ext_doc/index")."'>Help</a>";}
 				break;
diff --git a/themes/lite/view.theme.php b/themes/lite/view.theme.php
index a30c5b1d..c86ceb92 100644
--- a/themes/lite/view.theme.php
+++ b/themes/lite/view.theme.php
@@ -44,7 +44,7 @@ class CustomViewImageTheme extends ViewImageTheme {
 			$html .= "<br>Source: <a href='$h_source'>link</a>";
 		}
 
-		if(file_exists("ext/rating")) {
+		if(class_exists("Ratings")) {
 			if($image->rating == null || $image->rating == "u"){
 				$image->rating = "u";
 			}