diff --git a/tools/testing/ktest/ktest.pl b/tools/testing/ktest/ktest.pl
index 7bce412..76a5964 100755
--- a/tools/testing/ktest/ktest.pl
+++ b/tools/testing/ktest/ktest.pl
@@ -396,6 +396,13 @@
     return $ret;
 }
 
+sub value_defined {
+    my ($val) = @_;
+
+    return defined($variable{$2}) ||
+	defined($opt{$2});
+}
+
 sub process_if {
     my ($name, $value) = @_;
 
@@ -409,13 +416,21 @@
 	return $ret;
     }
 
+    if ($val =~ /^\s*(NOT\s*)?DEFINED\s+(\S+)\s*$/) {
+	if (defined $1) {
+	    return !value_defined($2);
+	} else {
+	    return value_defined($2);
+	}
+    }
+
     if ($val =~ /^\s*0\s*$/) {
 	return 0;
     } elsif ($val =~ /^\s*\d+\s*$/) {
 	return 1;
     }
 
-    die ("$name: $.: Undefined variable $val in if statement\n");
+    die ("$name: $.: Undefined content $val in if statement\n");
     return 1;
 }
 
diff --git a/tools/testing/ktest/sample.conf b/tools/testing/ktest/sample.conf
index 0fd3ca3..7b49f07 100644
--- a/tools/testing/ktest/sample.conf
+++ b/tools/testing/ktest/sample.conf
@@ -137,6 +137,23 @@
 # ELSE
 # BUILD_TYPE = useconfig:${CONFIG_DIR}/config-64
 #
+# The DEFINED keyword can be used by the IF statements too.
+# It returns true if the given config variable or option has been defined
+# or false otherwise.
+#
+# 
+# DEFAULTS IF DEFINED USE_CC
+# CC := ${USE_CC}
+# ELSE
+# CC := gcc
+#
+#
+# As well as NOT DEFINED.
+#
+# DEFAULTS IF NOT DEFINED MAKE_CMD
+# MAKE_CMD := make ARCH=x86
+#
+#
 #
 # INCLUDE file
 #