diff --git a/includes/theme.inc b/includes/theme.inc
index 44946cf53bcb447686e250b5f00839d2e79615dc..c5015865d9d110e6ed8b060697cfeb07b770926b 100644
--- a/includes/theme.inc
+++ b/includes/theme.inc
@@ -2364,8 +2364,19 @@ function theme_get_suggestions($args, $base, $delimiter = '__') {
   $suggestions = array();
   $prefix = $base;
   foreach ($args as $arg) {
-    // Remove slashes or null per SA-CORE-2009-003.
-    $arg = str_replace(array("/", "\\", "\0"), '', $arg);
+    // Remove slashes or null per SA-CORE-2009-003 and change - (hyphen) to _
+    // (underscore).
+    //
+    // When we discover templates in @see drupal_find_theme_templates,
+    // hyphens (-) are converted to underscores (_) before the theme hook
+    // is registered. We do this because the hyphens used for delimiters
+    // in hook suggestions cannot be used in the function names of the
+    // associated preprocess functions. Any page templates designed to be used
+    // on paths that contain a hyphen are also registered with these hyphens
+    // converted to underscores so here we must convert any hyphens in path
+    // arguments to underscores here before fetching theme hook suggestions
+    // to ensure the templates are appropriately recognized.
+    $arg = str_replace(array("/", "\\", "\0", '-'), array('', '', '', '_'), $arg);
     // The percent acts as a wildcard for numeric arguments since
     // asterisks are not valid filename characters on many filesystems.
     if (is_numeric($arg)) {