diff --git a/data/supported-extensions b/data/supported-extensions
index 33ef033..222e0f4 100644
--- a/data/supported-extensions
+++ b/data/supported-extensions
@@ -79,6 +79,7 @@ pdo_pgsql 5.5 5.6 7.0 7.1 7.2 7.3 7.4 8.0 8.1 8.2
 pdo_sqlsrv 7.0 7.1 7.2 7.3 7.4 8.0 8.1 8.2
 pgsql 5.5 5.6 7.0 7.1 7.2 7.3 7.4 8.0 8.1 8.2
 php_trie 7.3 7.4 8.0 8.1 8.2
+pkcs11 7.4 8.0 8.1 8.2
 pq 7.0 7.1 7.2 7.3 7.4 8.0 8.1 8.2
 propro 5.5 5.6 7.0 7.1 7.2 7.3 7.4
 protobuf 5.5 5.6 7.0 7.1 7.2 7.3 7.4 8.0 8.1 8.2
diff --git a/install-php-extensions b/install-php-extensions
index bd25a65..d984020 100755
--- a/install-php-extensions
+++ b/install-php-extensions
@@ -1123,6 +1123,12 @@ buildRequiredPackageLists() {
 			php_trie@alpine)
 				buildRequiredPackageLists_persistent="$buildRequiredPackageLists_persistent libstdc++"
 				;;
+			pkcs11@alpine)
+				buildRequiredPackageLists_persistent="$buildRequiredPackageLists_persistent softhsm"
+				;;
+			pkcs11@debian)
+				buildRequiredPackageLists_persistent="$buildRequiredPackageLists_persistent libsofthsm2"
+				;;
 			pspell@alpine)
 				buildRequiredPackageLists_persistent="$buildRequiredPackageLists_persistent aspell-libs $(expandASpellDictionaries)"
 				buildRequiredPackageLists_volatile="$buildRequiredPackageLists_volatile aspell-dev"
diff --git a/scripts/tests/pkcs11 b/scripts/tests/pkcs11
new file mode 100755
index 0000000..27413ad
--- /dev/null
+++ b/scripts/tests/pkcs11
@@ -0,0 +1,13 @@
+#!/usr/bin/env php
+<?php
+
+require_once __DIR__ . '/_bootstrap.php';
+
+$module = new Pkcs11\Module('/usr/lib/softhsm/libsofthsm2.so');
+$moduleInfo = $module->getInfo();
+if (!is_array($moduleInfo)) {
+    fwrite(STDERR, "Pkcs11\\Module::getInfo() should return an array\n");
+}
+if (!isset($moduleInfo['manufacturerID']) || $moduleInfo['manufacturerID'] !== 'SoftHSM') {
+    fwrite(STDERR, "Unexpected return value of Pkcs11\\Module::getInfo()\n");
+}