diff --git a/lib/maxmind/MaxMind/CHANGELOG.md b/lib/maxmind/MaxMind/CHANGELOG.md
index 7b74978773c..4c89f0cc982 100644
--- a/lib/maxmind/MaxMind/CHANGELOG.md
+++ b/lib/maxmind/MaxMind/CHANGELOG.md
@@ -1,6 +1,14 @@
 CHANGELOG
 =========
 
+1.11.0
+-------------------
+
+* Replace runtime define of a constant to facilitate opcache preloading.
+  Reported by vedadkajtaz. GitHub #134.
+* Resolve minor issue found by the Clang static analyzer in the C
+  extension.
+
 1.10.1 (2021-04-14)
 -------------------
 
diff --git a/lib/maxmind/MaxMind/Db/Reader/Decoder.php b/lib/maxmind/MaxMind/Db/Reader/Decoder.php
index 4b00456413f..babaed878c7 100644
--- a/lib/maxmind/MaxMind/Db/Reader/Decoder.php
+++ b/lib/maxmind/MaxMind/Db/Reader/Decoder.php
@@ -7,13 +7,6 @@ namespace MaxMind\Db\Reader;
 // @codingStandardsIgnoreLine
 use RuntimeException;
 
-/*
- * @ignore
- *
- * We subtract 1 from the log to protect against precision loss.
- */
-\define(__NAMESPACE__ . '\_MM_MAX_INT_BYTES', (int) ((log(\PHP_INT_MAX, 2) - 1) / 8));
-
 class Decoder
 {
     /**
@@ -316,11 +309,11 @@ class Decoder
 
         $integer = 0;
 
-        // PHP integers are signed. _MM_MAX_INT_BYTES is the number of
+        // PHP integers are signed. PHP_INT_SIZE - 1 is the number of
         // complete bytes that can be converted to an integer. However,
         // we can convert another byte if the leading bit is zero.
-        $useRealInts = $byteLength <= _MM_MAX_INT_BYTES
-            || ($byteLength === _MM_MAX_INT_BYTES + 1 && (\ord($bytes[0]) & 0x80) === 0);
+        $useRealInts = $byteLength <= \PHP_INT_SIZE - 1
+            || ($byteLength === \PHP_INT_SIZE && (\ord($bytes[0]) & 0x80) === 0);
 
         for ($i = 0; $i < $byteLength; ++$i) {
             $part = \ord($bytes[$i]);
@@ -344,7 +337,7 @@ class Decoder
 
     private function sizeFromCtrlByte(int $ctrlByte, int $offset): array
     {
-        $size = $ctrlByte & 0x1f;
+        $size = $ctrlByte & 0x1F;
 
         if ($size < 29) {
             return [$size, $offset];
diff --git a/lib/maxmind/MaxMind/composer.json b/lib/maxmind/MaxMind/composer.json
index 8d9f9d50613..26d48730125 100644
--- a/lib/maxmind/MaxMind/composer.json
+++ b/lib/maxmind/MaxMind/composer.json
@@ -24,7 +24,7 @@
         "ext-maxminddb": "<1.10.1,>=2.0.0"
     },
     "require-dev": {
-        "friendsofphp/php-cs-fixer": "*",
+        "friendsofphp/php-cs-fixer": "3.*",
         "phpunit/phpunit": ">=8.0.0,<10.0.0",
         "php-coveralls/php-coveralls": "^2.1",
         "phpunit/phpcov": ">=6.0.0",
diff --git a/lib/thirdpartylibs.xml b/lib/thirdpartylibs.xml
index 47118aed1ce..3891920e4af 100644
--- a/lib/thirdpartylibs.xml
+++ b/lib/thirdpartylibs.xml
@@ -413,7 +413,7 @@ All rights reserved.</copyright>
     <location>maxmind/MaxMind</location>
     <name>MaxMind DB Reader API</name>
     <description>PHP API for reading MaxMind DB files.</description>
-    <version>1.10.1</version>
+    <version>1.11.0</version>
     <license>Apache</license>
     <licenseversion>2.0</licenseversion>
     <repository>https://github.com/maxmind/MaxMind-DB-Reader-php/</repository>