diff --git a/includes/common.inc b/includes/common.inc
index 9ec58b08e3e5988eb3f09ef92f5270f144c74ae2..c9127a5bda4b9df9fb914a0454a9551bd94ed052 100644
--- a/includes/common.inc
+++ b/includes/common.inc
@@ -1728,19 +1728,22 @@ function drupal_get_css($css = NULL) {
           unset($types[$type][$file]);
           continue;
         }
-        if (!$preprocess || !($is_writable && $preprocess_css)) {
-          // If a CSS file is not to be preprocessed and it's a module CSS file, it needs to *always* appear at the *top*,
-          // regardless of whether preprocessing is on or off.
-          if (!$preprocess && $type == 'module') {
-            $no_module_preprocess .= '<link type="text/css" rel="stylesheet" media="' . $media . '" href="' . base_path() . $file . $query_string . '" />' . "\n";
-          }
-          // If a CSS file is not to be preprocessed and it's a theme CSS file, it needs to *always* appear at the *bottom*,
-          // regardless of whether preprocessing is on or off.
-          else if (!$preprocess && $type == 'theme') {
-            $no_theme_preprocess .= '<link type="text/css" rel="stylesheet" media="' . $media . '" href="' . base_path() . $file . $query_string . '" />' . "\n";
-          }
-          else {
-            $output .= '<link type="text/css" rel="stylesheet" media="' . $media . '" href="' . base_path() . $file . $query_string . '" />' . "\n";
+        // Only include the stylesheet if it exists.
+        if (file_exists($file)) {
+          if (!$preprocess || !($is_writable && $preprocess_css)) {
+            // If a CSS file is not to be preprocessed and it's a module CSS file, it needs to *always* appear at the *top*,
+            // regardless of whether preprocessing is on or off.
+            if (!$preprocess && $type == 'module') {
+              $no_module_preprocess .= '<link type="text/css" rel="stylesheet" media="' . $media . '" href="' . base_path() . $file . $query_string . '" />' . "\n";
+            }
+            // If a CSS file is not to be preprocessed and it's a theme CSS file, it needs to *always* appear at the *bottom*,
+            // regardless of whether preprocessing is on or off.
+            else if (!$preprocess && $type == 'theme') {
+              $no_theme_preprocess .= '<link type="text/css" rel="stylesheet" media="' . $media . '" href="' . base_path() . $file . $query_string . '" />' . "\n";
+            }
+            else {
+              $output .= '<link type="text/css" rel="stylesheet" media="' . $media . '" href="' . base_path() . $file . $query_string . '" />' . "\n";
+            }
           }
         }
       }
diff --git a/includes/theme.inc b/includes/theme.inc
index 3a3e81cf8796f11b7ee26e78338f7048f8625531..dae26aa94969a661ffe655b00583a611e6a5d64b 100644
--- a/includes/theme.inc
+++ b/includes/theme.inc
@@ -449,9 +449,7 @@ function list_themes($refresh = FALSE) {
     foreach ($themes as $theme) {
       foreach ($theme->info['stylesheets'] as $media => $stylesheets) {
         foreach ($stylesheets as $stylesheet => $path) {
-          if (file_exists($path)) {
-            $theme->stylesheets[$media][$stylesheet] = $path;
-          }
+          $theme->stylesheets[$media][$stylesheet] = $path;
         }
       }
       foreach ($theme->info['scripts'] as $script => $path) {