diff --git a/src/object_classes_permissions.md b/src/object_classes_permissions.md
index 36cca3b..7ccd3ab 100644
--- a/src/object_classes_permissions.md
+++ b/src/object_classes_permissions.md
@@ -1892,7 +1892,7 @@ An object is instantiated for each process created by the system.
 
 *signull*
 
-- Test for exisitence of another process without sending a signal.
+- Test for existence of another process without sending a signal.
 
 *sigstop*