diff --git a/CHANGELOG.md b/CHANGELOG.md
index e1f3bb1..975626b 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -5,6 +5,15 @@ All notable changes to this project will be documented in this file.
 The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.1.0/),
 and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.html).
 
+## 2.7.1 — 2026-07-25
+
+- Reject trailing newlines in validated values: anchor regexes with `\z`
+  instead of `$` in `CounterExample::toExamplesCode()` (the examples-method
+  name passed to the reflection/replay path) and in `PropertyInterceptor` /
+  `SeedStorage` integer parsers. The latter two are hygiene only — env values
+  and `trim()`'ed seed-file contents already strip the newline before the
+  regex runs.
+
 ## 2.7.0 — 2026-07-25
 
 - Ship an AI agent skill (`resources/skills/rasuvaeff-property-testing/SKILL.md` +
diff --git a/src/CounterExample.php b/src/CounterExample.php
index bbf7e48..8ca0077 100644
--- a/src/CounterExample.php
+++ b/src/CounterExample.php
@@ -66,7 +66,7 @@ public function toJson(bool $pretty = false): string
 
     public function toExamplesCode(string $methodName = 'propertyExamples'): string
     {
-        if (preg_match('/^[A-Za-z_]\w*$/', $methodName) !== 1) {
+        if (preg_match('/^[A-Za-z_]\w*\z/', $methodName) !== 1) {
             throw new \InvalidArgumentException(sprintf('Invalid examples method name "%s"', $methodName));
         }
 
diff --git a/src/Internal/PropertyInterceptor.php b/src/Internal/PropertyInterceptor.php
index 4106e98..4430c0a 100644
--- a/src/Internal/PropertyInterceptor.php
+++ b/src/Internal/PropertyInterceptor.php
@@ -416,7 +416,7 @@ private function resolveRuns(int $runs): int
             return $runs;
         }
 
-        if (preg_match('/^\d+$/', $env) !== 1 || (int) $env < 1) {
+        if (preg_match('/^\d+\z/', $env) !== 1 || (int) $env < 1) {
             throw new \InvalidArgumentException(sprintf('PROPERTY_RUNS must be a positive integer, got "%s"', $env));
         }
 
@@ -478,7 +478,7 @@ private function resolveSeed(?int $attributeSeed): int
             return random_int(0, PHP_INT_MAX);
         }
 
-        if (preg_match('/^-?\d+$/', $env) !== 1) {
+        if (preg_match('/^-?\d+\z/', $env) !== 1) {
             throw new \InvalidArgumentException(sprintf('PROPERTY_SEED must be an integer, got "%s"', $env));
         }
 
diff --git a/src/Internal/SeedStorage.php b/src/Internal/SeedStorage.php
index b5aa1be..3f96f98 100644
--- a/src/Internal/SeedStorage.php
+++ b/src/Internal/SeedStorage.php
@@ -51,7 +51,7 @@ public function recall(string $id): ?int
 
         $content = file_get_contents($file);
 
-        if ($content === false || preg_match('/^-?\d+$/', trim($content)) !== 1) {
+        if ($content === false || preg_match('/^-?\d+\z/', trim($content)) !== 1) {
             return null;
         }
 
diff --git a/tests/CounterExampleTest.php b/tests/CounterExampleTest.php
index add025e..f0de22a 100644
--- a/tests/CounterExampleTest.php
+++ b/tests/CounterExampleTest.php
@@ -102,6 +102,12 @@ public function rejectsInvalidExamplesMethodName(): void
         (new CounterExample(1, 0, [], []))->toExamplesCode('not-valid');
     }
 
+    #[ExpectException(\InvalidArgumentException::class)]
+    public function rejectsExamplesMethodNameWithTrailingNewline(): void
+    {
+        (new CounterExample(1, 0, [], []))->toExamplesCode("validName\n");
+    }
+
     #[ExpectException(\LogicException::class)]
     public function refusesToGenerateNonRunnableObjectExampleCode(): void
     {