diff --git a/src/Data/Yaml/YamlLight/Lens.hs b/src/Data/Yaml/YamlLight/Lens.hs
--- a/src/Data/Yaml/YamlLight/Lens.hs
+++ b/src/Data/Yaml/YamlLight/Lens.hs
@@ -140,6 +140,15 @@
   fromYaml _ = Nothing
   toYaml = YStr . BC.pack . show
 
+instance AsYaml Bool where
+  fromYaml (YStr s) = case () of
+                        _ | s == BC.pack "true"  -> Just True
+                          | s == BC.pack "false" -> Just False
+                          | otherwise            -> Nothing
+  fromYaml _ = Nothing
+  toYaml True  = YStr $ BC.pack "true"
+  toYaml False = YStr $ BC.pack "false"
+
 -- | Convert between YAML values and corresponding common Haskell
 -- values.
 --
diff --git a/yaml-light-lens.cabal b/yaml-light-lens.cabal
--- a/yaml-light-lens.cabal
+++ b/yaml-light-lens.cabal
@@ -1,5 +1,5 @@
 name:                yaml-light-lens
-version:             0.1.1
+version:             0.2.0.1
 synopsis:            Lens interface to yaml-light.
 -- description:         
 license:             BSD3
@@ -22,7 +22,7 @@
                        bytestring,
                        bytestring-lexing >= 0.4.3,
                        containers,
-                       lens >= 3.8 && < 3.10,
+                       lens >= 3.8 && < 3.11,
                        yaml-light >= 0.1 && < 0.2
   hs-source-dirs:      src
   ghc-options:         -Wall -fno-warn-orphans