diff --git a/.htaccess b/.htaccess
index 6f9123d14b1..b1ee36bf4c3 100644
--- a/.htaccess
+++ b/.htaccess
@@ -116,13 +116,13 @@ AddEncoding gzip svgz
   # RewriteBase /
 
   # Redirect common PHP files to their new locations.
-  RewriteCond %{REQUEST_URI} ^(.*)?/(install.php) [OR]
-  RewriteCond %{REQUEST_URI} ^(.*)?/(rebuild.php)
+  RewriteCond %{REQUEST_URI} ^(.*)?/(install\.php) [OR]
+  RewriteCond %{REQUEST_URI} ^(.*)?/(rebuild\.php)
   RewriteCond %{REQUEST_URI} !core
   RewriteRule ^ %1/core/%2 [L,QSA,R=301]
 
   # Rewrite install.php during installation to see if mod_rewrite is working
-  RewriteRule ^core/install.php core/install.php?rewrite=ok [QSA,L]
+  RewriteRule ^core/install\.php core/install.php?rewrite=ok [QSA,L]
 
   # Pass all requests not referring directly to files in the filesystem to
   # index.php.
@@ -138,11 +138,11 @@ AddEncoding gzip svgz
   # Allow access to PHP files in /core (like authorize.php or install.php):
   RewriteCond %{REQUEST_URI} !/core/[^/]*\.php$
   # Allow access to test-specific PHP files:
-  RewriteCond %{REQUEST_URI} !/core/modules/system/tests/https?.php
+  RewriteCond %{REQUEST_URI} !/core/modules/system/tests/https?\.php
   # Allow access to Statistics module's custom front controller.
   # Copy and adapt this rule to directly execute PHP files in contributed or
   # custom modules or to run another PHP application in the same directory.
-  RewriteCond %{REQUEST_URI} !/core/modules/statistics/statistics.php$
+  RewriteCond %{REQUEST_URI} !/core/modules/statistics/statistics\.php$
   # Deny access to any other PHP files that do not match the rules above.
   # Specifically, disallow autoload.php from being served directly.
   RewriteRule "^(.+/.*|autoload)\.php($|/)" - [F]
diff --git a/core/assets/scaffold/files/htaccess b/core/assets/scaffold/files/htaccess
index 6f9123d14b1..b1ee36bf4c3 100644
--- a/core/assets/scaffold/files/htaccess
+++ b/core/assets/scaffold/files/htaccess
@@ -116,13 +116,13 @@ AddEncoding gzip svgz
   # RewriteBase /
 
   # Redirect common PHP files to their new locations.
-  RewriteCond %{REQUEST_URI} ^(.*)?/(install.php) [OR]
-  RewriteCond %{REQUEST_URI} ^(.*)?/(rebuild.php)
+  RewriteCond %{REQUEST_URI} ^(.*)?/(install\.php) [OR]
+  RewriteCond %{REQUEST_URI} ^(.*)?/(rebuild\.php)
   RewriteCond %{REQUEST_URI} !core
   RewriteRule ^ %1/core/%2 [L,QSA,R=301]
 
   # Rewrite install.php during installation to see if mod_rewrite is working
-  RewriteRule ^core/install.php core/install.php?rewrite=ok [QSA,L]
+  RewriteRule ^core/install\.php core/install.php?rewrite=ok [QSA,L]
 
   # Pass all requests not referring directly to files in the filesystem to
   # index.php.
@@ -138,11 +138,11 @@ AddEncoding gzip svgz
   # Allow access to PHP files in /core (like authorize.php or install.php):
   RewriteCond %{REQUEST_URI} !/core/[^/]*\.php$
   # Allow access to test-specific PHP files:
-  RewriteCond %{REQUEST_URI} !/core/modules/system/tests/https?.php
+  RewriteCond %{REQUEST_URI} !/core/modules/system/tests/https?\.php
   # Allow access to Statistics module's custom front controller.
   # Copy and adapt this rule to directly execute PHP files in contributed or
   # custom modules or to run another PHP application in the same directory.
-  RewriteCond %{REQUEST_URI} !/core/modules/statistics/statistics.php$
+  RewriteCond %{REQUEST_URI} !/core/modules/statistics/statistics\.php$
   # Deny access to any other PHP files that do not match the rules above.
   # Specifically, disallow autoload.php from being served directly.
   RewriteRule "^(.+/.*|autoload)\.php($|/)" - [F]