diff --git a/doc/10-icinga-template-library.md b/doc/10-icinga-template-library.md
index f827fd78f..9311f1552 100644
--- a/doc/10-icinga-template-library.md
+++ b/doc/10-icinga-template-library.md
@@ -3493,13 +3493,14 @@ compared to thresholds. More details can be found on [this blog entry](http://sy
 
 Custom variables passed as [command parameters](03-monitoring-basics.md#command-passing-parameters):
 
-Name         | Description
--------------|-----------------------------------------------------------------------------------------------------------------------
-mem_used     | **Optional.** Tell the plugin to check for used memory in opposite of **mem_free**. Must specify one of these as true.
-mem_free     | **Optional.** Tell the plugin to check for free memory in opposite of **mem_used**. Must specify one of these as true.
-mem_cache    | **Optional.** If set to true, plugin will count cache as free memory. Defaults to false.
-mem_warning  | **Required.** Specify the warning threshold as number interpreted as percent.
-mem_critical | **Required.** Specify the critical threshold as number interpreted as percent.
+Name          | Description
+--------------|-----------------------------------------------------------------------------------------------------------------------
+mem_used      | **Optional.** Tell the plugin to check for used memory to the exclusion of **mem_free** and **mem_available**. Must specify one of these as true.
+mem_free      | **Optional.** Tell the plugin to check for free memory to the exclusion of **mem_used** and **mem_available**. Must specify one of these as true.
+mem_available | **Optional.** Tell the plugin to check available memory to the exclusion of **mem_free** and **mem_used**. Must specify one of these as true.
+mem_cache     | **Optional.** If set to true, plugin will count cache as free memory. Defaults to false.
+mem_warning   | **Required.** Specify the warning threshold as number interpreted as percent.
+mem_critical  | **Required.** Specify the critical threshold as number interpreted as percent.
 
 #### sar-perf <a id="plugin-contrib-command-sar-perf"></a>
 
diff --git a/itl/plugins-contrib.d/operating-system.conf b/itl/plugins-contrib.d/operating-system.conf
index afab177f0..41a46e8f9 100644
--- a/itl/plugins-contrib.d/operating-system.conf
+++ b/itl/plugins-contrib.d/operating-system.conf
@@ -8,6 +8,10 @@ object CheckCommand "mem" {
 			set_if = "$mem_used$"
 			description = "Check USED memory"
 		}
+		"-a" = {
+			set_if = "$mem_available$"
+			description = "Check AVAILABLE memory"
+		}
 		"-f" = {
 			set_if = "$mem_free$"
 			description = "Check FREE memory"
@@ -28,6 +32,7 @@ object CheckCommand "mem" {
 
 	vars.mem_used = false
 	vars.mem_free = false
+	vars.mem_available = false
 	vars.mem_cache = false
 }