diff --git a/src/Regex/private.php b/src/Regex/private.php
index f6e8093..7e5ebea 100644
--- a/src/Regex/private.php
+++ b/src/Regex/private.php
@@ -17,3 +17,15 @@ function _unprefixed(string $string, string $prefix): string {
     }
     return $string;
 }
+
+function _errorMessage(string $phpMessage, string $methodName, string $errorPattern): string {
+    $errorMessage = _unprefixed($phpMessage, "$methodName(): ");
+    [$pcreMessage, $offset] = \explode(' at offset ', $errorMessage);
+    $compilationPrefix = 'Compilation failed: ';
+    if (\str_starts_with($pcreMessage, $compilationPrefix)) {
+        return _denoted(
+            \subStr($pcreMessage, \strLen($compilationPrefix)),
+            $errorPattern, $offset);
+    }
+    return $errorMessage;
+}
diff --git a/src/public.php b/src/public.php
index 5f920a3..57d5130 100644
--- a/src/public.php
+++ b/src/public.php
@@ -1,9 +1,8 @@
 <?php
 
 use Regex\MalformedRegex;
-use function Regex\_denoted;
+use function Regex\_errorMessage;
 use function Regex\_pcre_pattern;
-use function Regex\_unprefixed;
 
 function re_test(string $pattern, string $subject, string $modifiers = null): bool {
     $match = \preg_match(_pcre_pattern($pattern, $modifiers), $subject);
@@ -12,13 +11,5 @@ function re_test(string $pattern, string $subject, string $modifiers = null): bo
         return $match;
     }
     \error_clear_last();
-    $errorMessage = _unprefixed($error['message'], 'preg_match(): ');
-    [$pcreMessage, $offset] = \explode(' at offset ', $errorMessage);
-    $compilationPrefix = 'Compilation failed: ';
-    if (\str_starts_with($pcreMessage, $compilationPrefix)) {
-        throw new MalformedRegex(_denoted(
-            \subStr($pcreMessage, \strLen($compilationPrefix)),
-            $pattern, $offset));
-    }
-    throw new MalformedRegex($errorMessage);
+    throw new MalformedRegex(_errorMessage($error['message'], 'preg_match', $pattern));
 }