diff --git a/imagecache.module b/imagecache.module
index 55d48ce..477b0d3 100644
--- a/imagecache.module
+++ b/imagecache.module
@@ -895,8 +895,17 @@ function theme_imagecache($presetname, $path, $alt = '', $title = '', $attribute
     'alt' => $alt,
     'title' => $title,
   );
-  if ($getsize && ($image = image_get_info(imagecache_create_path($presetname, $path)))) {
-    $ours += array('width' => $image['width'], 'height' => $image['height']);
+
+  if ($getsize) {
+    $cachepath = imagecache_create_path($presetname, $path);
+    if (!is_file($cachepath)) {
+      $preset = imagecache_preset_by_name($presetname);
+      $dst = imagecache_create_path($presetname, $path);
+      imagecache_build_derivative($preset['actions'], $path, $dst);
+    }
+    if ($image = image_get_info($cachepath)) {
+      $ours += array('width' => $image['width'], 'height' => $image['height']);
+    }
   }
 
   return '<img' . drupal_attributes($ours + $attributes) . '/>';