diff --git a/profiles/realtime/tuned.conf b/profiles/realtime/tuned.conf
index e1b6bcd..2592681 100644
--- a/profiles/realtime/tuned.conf
+++ b/profiles/realtime/tuned.conf
@@ -10,13 +10,17 @@ include = network-latency
 [variables]
 # User is responsible for updating variables.conf with variable content such as isolated_cores=X-Y 
 include = /etc/tuned/realtime-variables.conf
+
+# Fail if isolated_cores are not set
+assert1=${f:assertion_non_equal:isolated_cores unset:${isolated_cores}:\${isolated_cores}}
+
 # Non-isolated cores cpumask including offline cores
 not_isolated_cpumask = ${f:cpulist2hex_invert:${isolated_cores}}
 isolated_cores_expanded=${f:cpulist_unpack:${isolated_cores}}
 isolated_cores_present_expanded=${f:cpulist_present:${isolated_cores}}
 
 # Fail if isolated_cores contains CPUs which are not present
-assert=${f:assertion:isolated_cores contains present CPU(s):${isolated_cores_expanded}:${isolated_cores_present_expanded}}
+assert2=${f:assertion:isolated_cores contains present CPU(s):${isolated_cores_expanded}:${isolated_cores_present_expanded}}
 
 [sysctl]
 kernel.hung_task_timeout_secs = 600
diff --git a/tuned/profiles/functions/function_assertion_non_equal.py b/tuned/profiles/functions/function_assertion_non_equal.py
index f247163..a678bf2 100644
--- a/tuned/profiles/functions/function_assertion_non_equal.py
+++ b/tuned/profiles/functions/function_assertion_non_equal.py
@@ -20,6 +20,6 @@ class assertion_non_equal(base.Function):
 		if not super(self.__class__, self).execute(args):
 			return None
 		if args[1] != args[2]:
-			log.error("assertion non equal '%s' failed: '%s' == '%s'" % (args[0], args[1], args[2]))
-			raise InvalidProfileException("Assertion non equal '%s' failed." % args[0])
+			log.error("assertion '%s' failed: '%s' == '%s'" % (args[0], args[1], args[2]))
+			raise InvalidProfileException("Assertion '%s' failed." % args[0])
 		return None