diff --git a/thefuck/rules/brew_cask_dependency.py b/thefuck/rules/brew_cask_dependency.py
index 93c2915..8a0ad20 100644
--- a/thefuck/rules/brew_cask_dependency.py
+++ b/thefuck/rules/brew_cask_dependency.py
@@ -6,7 +6,7 @@ from thefuck.specific.brew import brew_available
 @for_app('brew')
 def match(command):
     return (u'install' in command.script_parts
-            and u'brew cask install' in command.stderr)
+            and u'brew cask install' in command.output)
 
 
 @eager
diff --git a/thefuck/rules/fab_command_not_found.py b/thefuck/rules/fab_command_not_found.py
index e87026e..05d6df0 100644
--- a/thefuck/rules/fab_command_not_found.py
+++ b/thefuck/rules/fab_command_not_found.py
@@ -3,7 +3,7 @@ from thefuck.utils import eager, get_closest, for_app
 
 @for_app('fab')
 def match(command):
-    return 'Warning: Command(s) not found:' in command.stderr
+    return 'Warning: Command(s) not found:' in command.output
 
 
 # We need different behavior then in get_all_matched_commands.