diff --git a/hlint.cabal b/hlint.cabal
--- a/hlint.cabal
+++ b/hlint.cabal
@@ -1,7 +1,7 @@
 cabal-version:      >= 1.6
 build-type:         Simple
 name:               hlint
-version:            1.8.18
+version:            1.8.19
 -- license is GPL v2 only
 license:            GPL
 license-file:       LICENSE
diff --git a/src/Hint/Lambda.hs b/src/Hint/Lambda.hs
--- a/src/Hint/Lambda.hs
+++ b/src/Hint/Lambda.hs
@@ -55,6 +55,9 @@
 f = bar &+& \x -> f (g x)
 foo = [\column -> set column [treeViewColumnTitle := printf "%s (match %d)" name (length candidnates)]]
 foo = [\x -> x]
+foo = [\m x -> insert x x m]
+foo a b c = bar (flux ++ quux) c where flux = a -- foo a b = bar (flux ++ quux)
+foo a b c = bar (flux ++ quux) c where flux = c
 </TEST>
 -}
 
@@ -64,6 +67,7 @@
 import Hint.Util
 import Hint.Type
 import Util
+import Data.Maybe
 
 
 lambdaHint :: DeclHint
@@ -71,9 +75,10 @@
 
 
 lambdaDecl :: Decl_ -> [Idea]
-lambdaDecl (toFunBind -> o@(FunBind _ [Match _ name pats (UnGuardedRhs _ bod) Nothing]))
-    | isLambda $ fromParen bod = [err "Redundant lambda" o $ uncurry reform $ fromLambda $ Lambda an pats bod]
-    | (pats2,bod2) <- etaReduce pats bod, length pats2 < length pats = [err "Eta reduce" o $ reform pats2 bod2]
+lambdaDecl (toFunBind -> o@(FunBind _ [Match _ name pats (UnGuardedRhs _ bod) bind]))
+    | isNothing bind, isLambda $ fromParen bod = [err "Redundant lambda" o $ uncurry reform $ fromLambda $ Lambda an pats bod]
+    | (pats2,bod2) <- etaReduce pats bod, length pats2 < length pats, pvars (drop (length pats2) pats) `disjoint` vars bind
+        = [err "Eta reduce" (reform pats bod) (reform pats2 bod2)]
         where reform p b = FunBind an [Match an name p (UnGuardedRhs an b) Nothing]
 lambdaDecl _ = []
 
diff --git a/src/Hint/Util.hs b/src/Hint/Util.hs
--- a/src/Hint/Util.hs
+++ b/src/Hint/Util.hs
@@ -35,7 +35,7 @@
 
 -- \x y -> f y x = flip f
 niceLambda [x,y] (view -> App2 op (view -> Var_ y1) (view -> Var_ x1))
-    | x == x1 && y == y1 = App an (toNamed "flip") op
+    | x == x1, y == y1, vars op `disjoint` [x,y] = App an (toNamed "flip") op
 
 -- \x -> f (b x) ==> f . b
 -- \x -> f $ b x ==> f . b