diff --git a/doc/developerguide/01-NewIcingaCheck.md b/doc/developerguide/01-NewIcingaCheck.md
index 965ec62..649c06d 100644
--- a/doc/developerguide/01-NewIcingaCheck.md
+++ b/doc/developerguide/01-NewIcingaCheck.md
@@ -44,6 +44,7 @@ For performance metrics you can provide a `Unit` to ensure your graphing is disp
 | B    | Bytes        | The input is indicated as quantity in bytes     |
 | KB   | Kilobytes    | The input is indicated as quantity in kilobytes |
 | MB   | Megabytes    | The input is indicated as quantity in megabytes |
+| GB   | Gigabytes    | The input is indicated as quantity in gigabytes |
 | TB   | Terabytes    | The input is indicated as quantity in terabytes |
 | c    | Counter      | A continues counter increasing values over time |
 
diff --git a/lib/icinga/enums/Icinga_IcingaEnums.psm1 b/lib/icinga/enums/Icinga_IcingaEnums.psm1
index e0267ae..c3fcd0f 100644
--- a/lib/icinga/enums/Icinga_IcingaEnums.psm1
+++ b/lib/icinga/enums/Icinga_IcingaEnums.psm1
@@ -26,6 +26,7 @@
     'B'  = 'bytes';
     'KB' = 'kilobytes';
     'MB' = 'megabytes';
+    'GB' = 'gigabytes';
     'TB' = 'terabytes';
     'c'  = 'counter';
 };