diff --git a/spec/kdump-lib_spec.sh b/spec/kdump-lib_spec.sh
index 8c91480..3d10006 100644
--- a/spec/kdump-lib_spec.sh
+++ b/spec/kdump-lib_spec.sh
@@ -48,4 +48,36 @@ Describe 'kdump-lib'
 		End
 	End
 
+	Describe 'prepare_cmdline()'
+		get_bootcpu_apicid() {
+			echo 1
+		}
+
+		get_watchdog_drvs() {
+			echo foo
+		}
+
+		add="disable_cpu_apicid=1 foo.pretimeout=0"
+
+		Parameters
+		       #test  cmdline       remove    add       result
+			"#1"  "a b c"       ""        ""        "a b c"
+			"#2"  "a b c"       "b"       ""        "a c"
+			"#3"  "a b=x c"     "b"       ""        "a c"
+			"#4"  "a b='x y' c" "b"       ""        "a c"
+			"#5"  "a b='x y' c" "b=x"     ""        "a c"
+			"#6"  "a b='x y' c" "b='x y'" ""        "a c"
+			"#7"  "a b c"       ""        "x"       "a b c x"
+			"#8"  "a b c"       ""        "x=1"     "a b c x=1"
+			"#9"  "a b c"       ""        "x='1 2'" "a b c x='1 2'"
+			"#10" "a b c"       "a"       "x='1 2'" "b c x='1 2'"
+			"#11" "a b c"       "x"       "x='1 2'" "a b c x='1 2'"
+		End
+
+		It "Test $1: should generate the correct kernel command line"
+			When call prepare_cmdline "$2" "$3" "$4"
+			The output should equal "$5 $add"
+		End
+	End
+
 End