diff --git a/composer.lock b/composer.lock
index 73c009d82..d3d577d9c 100644
--- a/composer.lock
+++ b/composer.lock
@@ -8,16 +8,16 @@
     "packages": [
         {
             "name": "composer/ca-bundle",
-            "version": "1.2.7",
+            "version": "1.2.8",
             "source": {
                 "type": "git",
                 "url": "https://github.com/composer/ca-bundle.git",
-                "reference": "95c63ab2117a72f48f5a55da9740a3273d45b7fd"
+                "reference": "8a7ecad675253e4654ea05505233285377405215"
             },
             "dist": {
                 "type": "zip",
-                "url": "https://api.github.com/repos/composer/ca-bundle/zipball/95c63ab2117a72f48f5a55da9740a3273d45b7fd",
-                "reference": "95c63ab2117a72f48f5a55da9740a3273d45b7fd",
+                "url": "https://api.github.com/repos/composer/ca-bundle/zipball/8a7ecad675253e4654ea05505233285377405215",
+                "reference": "8a7ecad675253e4654ea05505233285377405215",
                 "shasum": ""
             },
             "require": {
@@ -60,22 +60,21 @@
                 "ssl",
                 "tls"
             ],
-            "support": {
-                "irc": "irc://irc.freenode.org/composer",
-                "issues": "https://github.com/composer/ca-bundle/issues",
-                "source": "https://github.com/composer/ca-bundle/tree/1.2.7"
-            },
             "funding": [
                 {
                     "url": "https://packagist.com",
                     "type": "custom"
                 },
+                {
+                    "url": "https://github.com/composer",
+                    "type": "github"
+                },
                 {
                     "url": "https://tidelift.com/funding/github/packagist/composer/composer",
                     "type": "tidelift"
                 }
             ],
-            "time": "2020-04-08T08:27:21+00:00"
+            "time": "2020-08-23T12:54:47+00:00"
         },
         {
             "name": "composer/semver",
@@ -239,16 +238,16 @@
         },
         {
             "name": "composer/xdebug-handler",
-            "version": "1.4.2",
+            "version": "1.4.3",
             "source": {
                 "type": "git",
                 "url": "https://github.com/composer/xdebug-handler.git",
-                "reference": "fa2aaf99e2087f013a14f7432c1cd2dd7d8f1f51"
+                "reference": "ebd27a9866ae8254e873866f795491f02418c5a5"
             },
             "dist": {
                 "type": "zip",
-                "url": "https://api.github.com/repos/composer/xdebug-handler/zipball/fa2aaf99e2087f013a14f7432c1cd2dd7d8f1f51",
-                "reference": "fa2aaf99e2087f013a14f7432c1cd2dd7d8f1f51",
+                "url": "https://api.github.com/repos/composer/xdebug-handler/zipball/ebd27a9866ae8254e873866f795491f02418c5a5",
+                "reference": "ebd27a9866ae8254e873866f795491f02418c5a5",
                 "shasum": ""
             },
             "require": {
@@ -298,7 +297,7 @@
                     "type": "tidelift"
                 }
             ],
-            "time": "2020-06-04T11:16:35+00:00"
+            "time": "2020-08-19T10:27:58+00:00"
         },
         {
             "name": "justinrainbow/json-schema",
@@ -470,16 +469,16 @@
         },
         {
             "name": "seld/jsonlint",
-            "version": "1.8.0",
+            "version": "1.8.1",
             "source": {
                 "type": "git",
                 "url": "https://github.com/Seldaek/jsonlint.git",
-                "reference": "ff2aa5420bfbc296cf6a0bc785fa5b35736de7c1"
+                "reference": "3d5eb71705adfa34bd34b993400622932b2f62fd"
             },
             "dist": {
                 "type": "zip",
-                "url": "https://api.github.com/repos/Seldaek/jsonlint/zipball/ff2aa5420bfbc296cf6a0bc785fa5b35736de7c1",
-                "reference": "ff2aa5420bfbc296cf6a0bc785fa5b35736de7c1",
+                "url": "https://api.github.com/repos/Seldaek/jsonlint/zipball/3d5eb71705adfa34bd34b993400622932b2f62fd",
+                "reference": "3d5eb71705adfa34bd34b993400622932b2f62fd",
                 "shasum": ""
             },
             "require": {
@@ -515,10 +514,6 @@
                 "parser",
                 "validator"
             ],
-            "support": {
-                "issues": "https://github.com/Seldaek/jsonlint/issues",
-                "source": "https://github.com/Seldaek/jsonlint/tree/master"
-            },
             "funding": [
                 {
                     "url": "https://github.com/Seldaek",
@@ -529,7 +524,7 @@
                     "type": "tidelift"
                 }
             ],
-            "time": "2020-04-30T19:05:18+00:00"
+            "time": "2020-08-13T09:07:59+00:00"
         },
         {
             "name": "seld/phar-utils",
@@ -810,7 +805,7 @@
         },
         {
             "name": "symfony/polyfill-ctype",
-            "version": "v1.18.0",
+            "version": "v1.18.1",
             "source": {
                 "type": "git",
                 "url": "https://github.com/symfony/polyfill-ctype.git",
@@ -889,7 +884,7 @@
         },
         {
             "name": "symfony/polyfill-mbstring",
-            "version": "v1.18.0",
+            "version": "v1.18.1",
             "source": {
                 "type": "git",
                 "url": "https://github.com/symfony/polyfill-mbstring.git",
diff --git a/src/Composer/Command/SelfUpdateCommand.php b/src/Composer/Command/SelfUpdateCommand.php
index e5550d14e..fab414deb 100644
--- a/src/Composer/Command/SelfUpdateCommand.php
+++ b/src/Composer/Command/SelfUpdateCommand.php
@@ -271,7 +271,12 @@ TAGSPUBKEY
             $signature = json_decode($signature, true);
             $signature = base64_decode($signature['sha384']);
             $verified = 1 === openssl_verify(file_get_contents($tempFilename), $signature, $pubkeyid, $algo);
-            openssl_free_key($pubkeyid);
+
+            // PHP 8 automatically frees the key instance and deprecates the function
+            if (PHP_VERSION_ID < 80000) {
+                openssl_free_key($pubkeyid);
+            }
+
             if (!$verified) {
                 throw new \RuntimeException('The phar signature did not match the file you downloaded, this means your public keys are outdated or that the phar file is corrupt/has been modified');
             }