diff --git a/.htaccess b/.htaccess
index cf54b9b8c21..116acf42fb3 100644
--- a/.htaccess
+++ b/.htaccess
@@ -3,7 +3,7 @@
 #
 
 # Protect files and directories from prying eyes.
-<FilesMatch "\.(engine|inc|install|make|module|profile|po|sh|.*sql|theme|twig|tpl(\.php)?|xtmpl|yml)(~|\.sw[op]|\.bak|\.orig|\.save)?$|^(\.(?!well-known).*|Entries.*|Repository|Root|Tag|Template|composer\.(json|lock)|web\.config)$|^#.*#$|\.php(~|\.sw[op]|\.bak|\.orig|\.save)|$yarn.lock$|package.json$">
+<FilesMatch "\.(engine|inc|install|make|module|profile|po|sh|.*sql|theme|twig|tpl(\.php)?|xtmpl|yml)(~|\.sw[op]|\.bak|\.orig|\.save)?$|^(\.(?!well-known).*|Entries.*|Repository|Root|Tag|Template|composer\.(json|lock)|web\.config|yarn\.lock|package\.json)$|^#.*#$|\.php(~|\.sw[op]|\.bak|\.orig|\.save)$">
   <IfModule mod_authz_core.c>
     Require all denied
   </IfModule>
diff --git a/core/assets/scaffold/files/htaccess b/core/assets/scaffold/files/htaccess
index cf54b9b8c21..116acf42fb3 100644
--- a/core/assets/scaffold/files/htaccess
+++ b/core/assets/scaffold/files/htaccess
@@ -3,7 +3,7 @@
 #
 
 # Protect files and directories from prying eyes.
-<FilesMatch "\.(engine|inc|install|make|module|profile|po|sh|.*sql|theme|twig|tpl(\.php)?|xtmpl|yml)(~|\.sw[op]|\.bak|\.orig|\.save)?$|^(\.(?!well-known).*|Entries.*|Repository|Root|Tag|Template|composer\.(json|lock)|web\.config)$|^#.*#$|\.php(~|\.sw[op]|\.bak|\.orig|\.save)|$yarn.lock$|package.json$">
+<FilesMatch "\.(engine|inc|install|make|module|profile|po|sh|.*sql|theme|twig|tpl(\.php)?|xtmpl|yml)(~|\.sw[op]|\.bak|\.orig|\.save)?$|^(\.(?!well-known).*|Entries.*|Repository|Root|Tag|Template|composer\.(json|lock)|web\.config|yarn\.lock|package\.json)$|^#.*#$|\.php(~|\.sw[op]|\.bak|\.orig|\.save)$">
   <IfModule mod_authz_core.c>
     Require all denied
   </IfModule>
diff --git a/core/modules/system/tests/fixtures/HtaccessTest/package.json b/core/modules/system/tests/fixtures/HtaccessTest/package.json
new file mode 100644
index 00000000000..e69de29bb2d
diff --git a/core/modules/system/tests/fixtures/HtaccessTest/yarn.lock b/core/modules/system/tests/fixtures/HtaccessTest/yarn.lock
new file mode 100644
index 00000000000..e69de29bb2d
diff --git a/core/modules/system/tests/src/Functional/System/HtaccessTest.php b/core/modules/system/tests/src/Functional/System/HtaccessTest.php
index e932fa3b348..09046c446fc 100644
--- a/core/modules/system/tests/src/Functional/System/HtaccessTest.php
+++ b/core/modules/system/tests/src/Functional/System/HtaccessTest.php
@@ -91,6 +91,10 @@ class HtaccessTest extends BrowserTestBase {
     $file_paths["$path/composer.json"] = 403;
     $file_paths["$path/composer.lock"] = 403;
 
+    // Ensure package.json and yarn.lock cannot be accessed.
+    $file_paths["$path/package.json"] = 403;
+    $file_paths["$path/yarn.lock"] = 403;
+
     // Ensure web server configuration files cannot be accessed.
     $file_paths["$path/.htaccess"] = 403;
     $file_paths["$path/web.config"] = 403;