diff --git a/tests/beakerlib/built-in-functions/main.fmf b/tests/beakerlib/built-in-functions/main.fmf
new file mode 100644
index 000000000..999c4eccc
--- /dev/null
+++ b/tests/beakerlib/built-in-functions/main.fmf
@@ -0,0 +1,39 @@
+summary: built-in functions for various conversions. New functionality according to
+    BZ#1225135.
+description: ''
+contact: rhack@redhat.com
+component:
+  - tuned
+test: ./runtest.sh
+framework: beakerlib
+require:
+  - library(tuned/basic)
+recommend:
+  - tuned
+duration: 5m
+enabled: true
+tag:
+  - FedoraReady
+  - NoRHEL4
+  - NoRHEL5
+  - NoRHEL6
+  - TIPfail_infra
+  - TIPpass
+  - Tier1
+tier: '1'
+link:
+  - relates: https://bugzilla.redhat.com/show_bug.cgi?id=1225135
+adjust:
+  - enabled: false
+    when: distro == rhel-4, rhel-5, rhel-6, rhel-7
+    continue: false
+  - enabled: false
+    when: distro > rhel-8
+    continue: false
+  - enabled: false
+    when: distro > f-20
+    continue: false
+extra-nitrate: TC#0496876
+extra-summary: /CoreOS/tuned/Sanity/built-in-functions
+extra-task: /CoreOS/tuned/Sanity/built-in-functions
+id: b04c6dd3-4412-4bd9-b4c7-a5cc44172574
diff --git a/tests/beakerlib/built-in-functions/rhel7_function_testfunc.py b/tests/beakerlib/built-in-functions/rhel7_function_testfunc.py
new file mode 100644
index 000000000..1741e1ae2
--- /dev/null
+++ b/tests/beakerlib/built-in-functions/rhel7_function_testfunc.py
@@ -0,0 +1,16 @@
+import base
+from tuned.utils.commands import commands
+
+class testfunc(base.Function):
+    """
+    Test function
+    """
+    def __init__(self):
+        super(self.__class__, self).__init__("testfunc", 2)
+
+    def execute(self, args):
+        f = open(str(args[0]),'w')
+        f.write(str(args[1]))
+        f.close()
+        return str(args[1]) + 'returned'
+
diff --git a/tests/beakerlib/built-in-functions/rhel8_function_testfunc.py b/tests/beakerlib/built-in-functions/rhel8_function_testfunc.py
new file mode 100644
index 000000000..f6ced632c
--- /dev/null
+++ b/tests/beakerlib/built-in-functions/rhel8_function_testfunc.py
@@ -0,0 +1,16 @@
+from . import base
+from tuned.utils.commands import commands
+
+class testfunc(base.Function):
+    """
+    Test function
+    """
+    def __init__(self):
+        super(self.__class__, self).__init__("testfunc", 2)
+
+    def execute(self, args):
+        f = open(str(args[0]),'w')
+        f.write(str(args[1]))
+        f.close()
+        return str(args[1]) + 'returned'
+
diff --git a/tests/beakerlib/built-in-functions/runtest.sh b/tests/beakerlib/built-in-functions/runtest.sh
new file mode 100755
index 000000000..d5575e331
--- /dev/null
+++ b/tests/beakerlib/built-in-functions/runtest.sh
@@ -0,0 +1,81 @@
+#!/bin/bash
+# vim: dict+=/usr/share/beakerlib/dictionary.vim cpt=.,w,b,u,t,i,k
+# ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+#
+#   runtest.sh of /CoreOS/tuned/Sanity/built-in-functions
+#   Description: built-in functions for various conversions. New functionality according to BZ#1225135.
+#   Author: Robin Hack <rhack@redhat.com>
+#
+# ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+#
+#   Copyright Red Hat
+#
+#   SPDX-License-Identifier: GPL-2.0-or-later WITH GPL-CC-1.0
+#
+# ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+# Include Beaker environment
+. /usr/share/beakerlib/beakerlib.sh || exit 1
+
+PACKAGE="tuned"
+TUNED_DIR="/usr/lib/tuned"
+PROFILE="myprofile"
+
+
+rlJournalStart
+
+    rlPhaseStartSetup
+        rlAssertRpm $PACKAGE
+        rlImport "tuned/basic"
+        rlServiceStart "tuned"
+        tunedProfileBackup
+
+
+	PSITE_PATH=$(python3 -c "import site; print(site.getsitepackages()[3])")
+
+	# RHEL7 is not supported
+        if rlIsRHEL '>=8' || rlIsCentOS >= 8 || rlIsFedora; then
+	    TEST_SCRIPT="rhel8_function_testfunc.py"
+	fi
+	rlRun "cp -v ${TEST_SCRIPT} ${PSITE_PATH}/tuned/profiles/functions/function_testfunc.py"
+
+        # Prepare balanced profile
+        rlRun "mkdir $TUNED_DIR/$PROFILE"
+        rlRun -l "echo '[main]
+summary=My testing profile
+
+[variables]
+VAR1 = \${f:testfunc:/var/tmp/test1:IamTestingThis1}
+VAR2 = \${f:testfunc:/var/tmp/test2:\${VAR1}}
+cmd = echo
+cmd_out = \${f:exec:\${cmd}:output}
+VAR3 = \${f:testfunc:/var/tmp/test3:\${cmd_out}}
+
+' >> $TUNED_DIR/$PROFILE/tuned.conf"
+        rlRun -l "cat $TUNED_DIR/$PROFILE/tuned.conf"
+    
+	    echo > /var/log/tuned/tuned.log
+        rlRun "tuned-adm profile $PROFILE"
+        rlRun -l "cat /var/log/tuned/tuned.log"
+    rlPhaseEnd
+
+    rlPhaseStartTest
+        rlLog "Custom function and variable propagation"
+        rlAssertGrep "IamTestingThis1" "/var/tmp/test1"
+        rlAssertGrep "IamTestingThis1returned" "/var/tmp/test2"
+
+        rlLog "Built in 'exec' function"
+        rlAssertGrep "output" "/var/tmp/test3"	    
+    rlPhaseEnd
+
+    rlPhaseStartCleanup
+        rlFileRestore
+        tunedProfileRestore
+        rlServiceRestore "tuned"
+        rlRun "rm -rf $TUNED_DIR/$PROFILE"
+        rlRun "rm ${PSITE_PATH}/tuned/profiles/functions/function_testfunc.py"
+        rlRun "rm /var/tmp/test1 /var/tmp/test2"
+    rlPhaseEnd
+
+rlJournalPrintText
+rlJournalEnd