diff --git a/themes/bartik/template.php b/themes/bartik/template.php
index 7466e05ce..45fd42ac2 100644
--- a/themes/bartik/template.php
+++ b/themes/bartik/template.php
@@ -22,8 +22,8 @@ function bartik_preprocess_html(&$variables) {
   }
 
   // Add conditional stylesheets for IE
-  drupal_add_css(path_to_theme() . '/css/ie.css', array('group' => CSS_THEME, 'browsers' => array('IE' => 'lte IE 7', '!IE' => FALSE), 'preprocess' => FALSE));
-  drupal_add_css(path_to_theme() . '/css/ie6.css', array('group' => CSS_THEME, 'browsers' => array('IE' => 'IE 6', '!IE' => FALSE), 'preprocess' => FALSE));
+  drupal_add_css(drupal_get_path('theme', 'bartik') . '/css/ie.css', array('group' => CSS_THEME, 'browsers' => array('IE' => 'lte IE 7', '!IE' => FALSE), 'preprocess' => FALSE));
+  drupal_add_css(drupal_get_path('theme', 'bartik') . '/css/ie6.css', array('group' => CSS_THEME, 'browsers' => array('IE' => 'IE 6', '!IE' => FALSE), 'preprocess' => FALSE));
 }
 
 /**
diff --git a/themes/garland/template.php b/themes/garland/template.php
index ef7d4771d..db159a6f9 100644
--- a/themes/garland/template.php
+++ b/themes/garland/template.php
@@ -37,7 +37,7 @@ function garland_preprocess_html(&$variables) {
     $variables['classes_array'][] = 'fluid-width';
   }
   // Add conditional CSS for IE6.
-  drupal_add_css(path_to_theme() . '/fix-ie.css', array('group' => CSS_THEME, 'browsers' => array('IE' => 'lt IE 7', '!IE' => FALSE), 'preprocess' => FALSE));
+  drupal_add_css(drupal_get_path('theme', 'garland') . '/fix-ie.css', array('group' => CSS_THEME, 'browsers' => array('IE' => 'lt IE 7', '!IE' => FALSE), 'preprocess' => FALSE));
 }
 
 /**
diff --git a/themes/seven/template.php b/themes/seven/template.php
index 5c086fa49..bc831e747 100644
--- a/themes/seven/template.php
+++ b/themes/seven/template.php
@@ -17,11 +17,11 @@ function seven_preprocess_maintenance_page(&$vars) {
  */
 function seven_preprocess_html(&$vars) {
   // Add conditional CSS for IE8 and below.
-  drupal_add_css(path_to_theme() . '/ie.css', array('group' => CSS_THEME, 'browsers' => array('IE' => 'lte IE 8', '!IE' => FALSE), 'weight' => 999, 'preprocess' => FALSE));
+  drupal_add_css(drupal_get_path('theme', 'seven') . '/ie.css', array('group' => CSS_THEME, 'browsers' => array('IE' => 'lte IE 8', '!IE' => FALSE), 'weight' => 999, 'preprocess' => FALSE));
   // Add conditional CSS for IE7 and below.
-  drupal_add_css(path_to_theme() . '/ie7.css', array('group' => CSS_THEME, 'browsers' => array('IE' => 'lte IE 7', '!IE' => FALSE), 'weight' => 999, 'preprocess' => FALSE));
+  drupal_add_css(drupal_get_path('theme', 'seven') . '/ie7.css', array('group' => CSS_THEME, 'browsers' => array('IE' => 'lte IE 7', '!IE' => FALSE), 'weight' => 999, 'preprocess' => FALSE));
   // Add conditional CSS for IE6.
-  drupal_add_css(path_to_theme() . '/ie6.css', array('group' => CSS_THEME, 'browsers' => array('IE' => 'lte IE 6', '!IE' => FALSE), 'weight' => 999, 'preprocess' => FALSE));
+  drupal_add_css(drupal_get_path('theme', 'seven') . '/ie6.css', array('group' => CSS_THEME, 'browsers' => array('IE' => 'lte IE 6', '!IE' => FALSE), 'weight' => 999, 'preprocess' => FALSE));
 }
 
 /**