diff --git a/Puc/v4p4/UpdateChecker.php b/Puc/v4p4/UpdateChecker.php
index 7ead6fe..76eaf44 100644
--- a/Puc/v4p4/UpdateChecker.php
+++ b/Puc/v4p4/UpdateChecker.php
@@ -301,6 +301,14 @@ if ( !class_exists('Puc_v4p4_UpdateChecker', false) ):
 			//Let plugins/themes modify the update.
 			$update = apply_filters($this->getUniqueName('request_update_result'), $update, $httpResult);
 
+			// "Tested up to" field in the plugin metadata is supposed to be in form of "major.minor",
+			// while WordPress core's list_plugin_updates() expects the $update->tested field to be
+			// the exact version, e.g. "major.minor.patch", to say it's compatible. In other case it would
+			// show "Compatibility: Unknown". That kinda mimics how wordpress.org API handles the "tested" field.
+			if (isset($update->tested) && preg_match('/^\d+\.\d+$/', $update->tested)) {
+				$update->tested .= ".999";
+			}
+
 			if ( isset($update, $update->translations) ) {
 				//Keep only those translation updates that apply to this site.
 				$update->translations = $this->filterApplicableTranslations($update->translations);