diff --git a/web/app/libs/uoj-validate-lib.php b/web/app/libs/uoj-validate-lib.php
index 82b2d95..44a22c3 100644
--- a/web/app/libs/uoj-validate-lib.php
+++ b/web/app/libs/uoj-validate-lib.php
@@ -77,9 +77,9 @@ function is_short_string($str) {
 }
 
 function validateCodeforcesProblemId($str) {
-	return preg_match('/(|GYM)[1-9][0-9]{0,5}[A-Z][1-9]?/', $str) !== true;
+	return preg_match('/^(|GYM)[1-9][0-9]{0,5}[A-Z][1-9]?$/', $str);
 }
 
 function validateLuoguProblemId($str) {
-	return preg_match('/P[1-9][0-9]{4,5}/', $str) !== true;
+	return preg_match('/^P[1-9][0-9]{3,5}$/', $str);
 }