diff --git a/libs/plugins/function.html_select_date.php b/libs/plugins/function.html_select_date.php
index faeabb06..b86e9a25 100644
--- a/libs/plugins/function.html_select_date.php
+++ b/libs/plugins/function.html_select_date.php
@@ -14,8 +14,8 @@
  *                and end year values. (Monte)
  * -------------------------------------------------------------
  */
-require_once SMARTY_DIR . 'plugins/shared.make_timestamp.php';
-require_once SMARTY_DIR . 'plugins/function.html_options.php';
+require_once SMARTY_DIR . $this->plugins_dir . '/shared.make_timestamp.php';
+require_once SMARTY_DIR . $this->plugins_dir . '/function.html_options.php';
 function smarty_function_html_select_date($params, &$smarty)
 {
     /* Default values. */
diff --git a/libs/plugins/function.html_select_time.php b/libs/plugins/function.html_select_time.php
index 86075b98..3dc8b4a0 100644
--- a/libs/plugins/function.html_select_time.php
+++ b/libs/plugins/function.html_select_time.php
@@ -8,8 +8,8 @@
  * Purpose:  Prints the dropdowns for time selection
  * -------------------------------------------------------------
  */
-require_once SMARTY_DIR . 'plugins/shared.make_timestamp.php';
-require_once SMARTY_DIR . 'plugins/function.html_options.php';
+require_once SMARTY_DIR . $this->plugins_dir . '/shared.make_timestamp.php';
+require_once SMARTY_DIR . $this->plugins_dir . '/function.html_options.php';
 function smarty_function_html_select_time($params, &$smarty)
 {
     /* Default values. */
diff --git a/libs/plugins/modifier.date_format.php b/libs/plugins/modifier.date_format.php
index a8e83f1f..9fe49aa8 100644
--- a/libs/plugins/modifier.date_format.php
+++ b/libs/plugins/modifier.date_format.php
@@ -8,7 +8,7 @@
  * Purpose:  format datestamps via strftime
  * -------------------------------------------------------------
  */
-require_once SMARTY_DIR . 'plugins/shared.make_timestamp.php';
+require_once SMARTY_DIR . $this->plugins_dir . '/shared.make_timestamp.php';
 function smarty_modifier_date_format($string, $format="%b %e, %Y")
 {
     return strftime($format, smarty_make_timestamp($string));
diff --git a/plugins/function.html_select_date.php b/plugins/function.html_select_date.php
index faeabb06..b86e9a25 100644
--- a/plugins/function.html_select_date.php
+++ b/plugins/function.html_select_date.php
@@ -14,8 +14,8 @@
  *                and end year values. (Monte)
  * -------------------------------------------------------------
  */
-require_once SMARTY_DIR . 'plugins/shared.make_timestamp.php';
-require_once SMARTY_DIR . 'plugins/function.html_options.php';
+require_once SMARTY_DIR . $this->plugins_dir . '/shared.make_timestamp.php';
+require_once SMARTY_DIR . $this->plugins_dir . '/function.html_options.php';
 function smarty_function_html_select_date($params, &$smarty)
 {
     /* Default values. */
diff --git a/plugins/function.html_select_time.php b/plugins/function.html_select_time.php
index 86075b98..3dc8b4a0 100644
--- a/plugins/function.html_select_time.php
+++ b/plugins/function.html_select_time.php
@@ -8,8 +8,8 @@
  * Purpose:  Prints the dropdowns for time selection
  * -------------------------------------------------------------
  */
-require_once SMARTY_DIR . 'plugins/shared.make_timestamp.php';
-require_once SMARTY_DIR . 'plugins/function.html_options.php';
+require_once SMARTY_DIR . $this->plugins_dir . '/shared.make_timestamp.php';
+require_once SMARTY_DIR . $this->plugins_dir . '/function.html_options.php';
 function smarty_function_html_select_time($params, &$smarty)
 {
     /* Default values. */
diff --git a/plugins/modifier.date_format.php b/plugins/modifier.date_format.php
index a8e83f1f..9fe49aa8 100644
--- a/plugins/modifier.date_format.php
+++ b/plugins/modifier.date_format.php
@@ -8,7 +8,7 @@
  * Purpose:  format datestamps via strftime
  * -------------------------------------------------------------
  */
-require_once SMARTY_DIR . 'plugins/shared.make_timestamp.php';
+require_once SMARTY_DIR . $this->plugins_dir . '/shared.make_timestamp.php';
 function smarty_modifier_date_format($string, $format="%b %e, %Y")
 {
     return strftime($format, smarty_make_timestamp($string));