diff --git a/CHANGELOG.md b/CHANGELOG.md
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,3 +1,8 @@
+# 0.1.8.0
+
+* Added `assign` and `modifying` as synonyms for `.=` and `%=`.
+* Added `<%=`, `<<%=`, and `<<.=`.
+
 # 0.1.7.1
 
 * Added forgotten copyright/authorship information.
diff --git a/microlens-mtl.cabal b/microlens-mtl.cabal
--- a/microlens-mtl.cabal
+++ b/microlens-mtl.cabal
@@ -1,5 +1,5 @@
 name:                microlens-mtl
-version:             0.1.7.1
+version:             0.1.8.0
 synopsis:            microlens support for Reader/Writer/State from mtl
 description:
   This package contains functions (like 'view' or '+=') which work on 'MonadReader', 'MonadWriter', and 'MonadState' from the mtl package.
diff --git a/src/Lens/Micro/Mtl.hs b/src/Lens/Micro/Mtl.hs
--- a/src/Lens/Micro/Mtl.hs
+++ b/src/Lens/Micro/Mtl.hs
@@ -1,4 +1,5 @@
 {-# LANGUAGE
+CPP,
 MultiParamTypeClasses,
 FunctionalDependencies,
 FlexibleInstances,
@@ -18,12 +19,22 @@
 -}
 module Lens.Micro.Mtl
 (
+  -- * Getting
   view, preview,
   use, preuse,
+
+  -- * Zooming
   zoom,
   magnify,
-  (.=), (%=),
+
+  -- * Setting
+  (.=), assign,
+  (%=), modifying,
   (+=), (-=), (*=), (//=),
+
+  -- * Setting with passthrough
+  (<%=), (<<%=),
+  (<<.=),
 )
 where
 
@@ -104,6 +115,7 @@
 
 
 infix  4 .=, %=
+infix  4 <<.=, <<%=, <%=
 infix  4 +=, -=, *=, //=
 
 {- |
@@ -114,12 +126,21 @@
 @
 l '.=' x = 'State.modify' (l '.~' x)
 @
+
+If you also want to know the value that was replaced by ('.='), use ('<<.=').
 -}
 (.=) :: MonadState s m => ASetter s s a b -> b -> m ()
 l .= x = State.modify (l .~ x)
 {-# INLINE (.=) #-}
 
 {- |
+A synonym for ('.=').
+-}
+assign :: MonadState s m => ASetter s s a b -> b -> m ()
+assign l x = l .= x
+{-# INLINE assign #-}
+
+{- |
 Modify state by applying a function to a part of the state. An example:
 
 >>> execState (do _1 %= (+1); _2 %= reverse) (1,"hello")
@@ -131,8 +152,10 @@
 l '%=' f = 'State.modify' (l '%~' f)
 @
 
-There are also a few specialised versions of ('%=') which mimic C operators:
+If you also want to get the value before\/after the modification, use ('<<%=')\/('<%=').
 
+There are a few specialised versions of ('%=') which mimic C operators:
+
 * ('+=') for addition
 * ('-=') for substraction
 * ('*=') for multiplication
@@ -143,6 +166,13 @@
 {-# INLINE (%=) #-}
 
 {- |
+A synonym for ('%=').
+-}
+modifying :: (MonadState s m) => ASetter s s a b -> (a -> b) -> m ()
+modifying l f = l %= f
+{-# INLINE modifying #-}
+
+{- |
 Add a number to the target.
 
 @
@@ -185,3 +215,57 @@
 (//=) :: (MonadState s m, Fractional a) => ASetter s s a a -> a -> m ()
 l //= x = l %= (/x)
 {-# INLINE (//=) #-}
+
+{- |
+Modify state and return the modified (new) value.
+
+@
+l '<%=' f = do
+  l '%=' f
+  'use' l
+@
+-}
+(<%=) :: MonadState s m => LensLike ((,) b) s s a b -> (a -> b) -> m b
+l <%= f = l %%= (\a -> (a, a)) . f
+{-# INLINE (<%=) #-}
+
+{- |
+Modify state and return the old value (i.e. as it was before the modificaton).
+
+@
+l '<<%=' f = do
+  old <- 'use' l
+  l '%=' f
+  return old
+@
+-}
+(<<%=) :: MonadState s m => LensLike ((,) a) s s a b -> (a -> b) -> m a
+l <<%= f = l %%= (\a -> (a, f a))
+{-# INLINE (<<%=) #-}
+
+{- |
+Set state and return the old value.
+
+@
+l '<<.=' b = do
+  old <- 'use' l
+  l '.=' f
+  return old
+@
+-}
+(<<.=) :: MonadState s m => LensLike ((,) a) s s a b -> b -> m a
+l <<.= b = l %%= (\a -> (a, b))
+{-# INLINE (<<.=) #-}
+
+(%%=) :: MonadState s m => LensLike ((,) r) s s a b -> (a -> (r, b)) -> m r
+#if MIN_VERSION_mtl(2,1,1)
+l %%= f = State.state (l f)
+#else
+l %%= f = do
+  (r, s) <- State.gets (l f)
+  State.put s
+  return r
+#endif
+{-# INLINE (%%=) #-}
+
+infix 4 %%=