diff --git management/univention-ldap/conffiles/etc/ldap/slapd.conf.d/25univention-ldap-server_local-schema management/univention-ldap/conffiles/etc/ldap/slapd.conf.d/25univention-ldap-server_local-schema
index df71d806fb..d628098f79 100644
--- management/univention-ldap/conffiles/etc/ldap/slapd.conf.d/25univention-ldap-server_local-schema
+++ management/univention-ldap/conffiles/etc/ldap/slapd.conf.d/25univention-ldap-server_local-schema
@@ -1,8 +1,9 @@
-@!@
 
+@!@
 import os
+import os.path
 import re
-import subprocess
+from univention.config_registry.handler import run_filter
 
 
 def getRegisteredFiles():
@@ -11,18 +12,21 @@ def getRegisteredFiles():
 	for f in os.listdir(registeredDirectory):
 		for line in open(os.path.join(registeredDirectory, f), 'r').readlines():
 			if line.startswith('File: '):
-				files.append(line.replace('File: ', '').strip())
+				fn = line.replace('File: ', '').strip()
+				if fn.startswith('etc/ldap/slapd.conf.d'):
+					files.append(fn)
 			elif line.startswith('Subfile: '):
-				files.append(line.replace('Subfile: ', '').strip())
+				fn = line.replace('Subfile: ', '').strip()
+				if fn.startswith('etc/ldap/slapd.conf.d'):
+					files.append(fn)
 
 	return files
 
 
-def isSchemaFileIncluded(schemaFile):
+def ucr_filter_files(registeredFiles):
 	directoryPath = '/etc/univention/templates/files/etc/ldap/slapd.conf.d/'
 
-	registeredFiles = getRegisteredFiles()
-
+	checklist = []
 	for f in os.listdir(directoryPath):
 		if f == '25univention-ldap-server_local-schema' or f.startswith('.'):
 			continue
@@ -31,21 +35,27 @@ def isSchemaFileIncluded(schemaFile):
 		if not 'etc/ldap/slapd.conf.d/%s' % f in registeredFiles:
 			continue
 
-		p1 = subprocess.Popen(["cat", "/etc/univention/templates/files/etc/ldap/slapd.conf.d/%s" % f], stdout=subprocess.PIPE)
-		p2 = subprocess.Popen(["ucr", "filter"], stdin=p1.stdout, stdout=subprocess.PIPE)
-		p1.stdout.close()
-		output = p2.communicate()[0].decode('utf-8', 'replace')
-		pattern = re.compile('include.*%s' % schemaFile)
-		for line in output.split('\n'):
-			if line and pattern.match(line):
-				return True
+		checklist.append(f)
+
+	output = ""
+	if checklist:
+		for fn in checklist:
+			with open('/etc/univention/templates/files/etc/ldap/slapd.conf.d/%s' % (fn,), 'r') as f:
+				output += run_filter(f.read(), configRegistry)
+	return output
 
-	return False
+
+def isSchemaFileIncluded(schemaFile, ucr_filtered_output):
+	return re.search('\ninclude.*%s\n' % schemaFile, ucr_filtered_output) is not None
 
 
 if configRegistry.get('ldap/server/type', 'slave') == 'master':
 	if os.path.exists('/var/lib/univention-ldap/local-schema'):
-		for schemaFile in sorted(os.listdir('/var/lib/univention-ldap/local-schema')):
-			if not isSchemaFileIncluded(schemaFile):
+
+		registeredFiles = getRegisteredFiles()
+		ucr_filtered_output = ucr_filter_files(registeredFiles)
+
+		for schemaFile in os.listdir('/var/lib/univention-ldap/local-schema'):
+			if not isSchemaFileIncluded(schemaFile, ucr_filtered_output):
 				print('include         /var/lib/univention-ldap/local-schema/%s' % schemaFile)
 @!@