diff --git a/juvix-stdlib b/juvix-stdlib
index 216cb609cb..17f22fcec5 160000
--- a/juvix-stdlib
+++ b/juvix-stdlib
@@ -1 +1 @@
-Subproject commit 216cb609cbe5aec9badea858f151a5ea400f2e66
+Subproject commit 17f22fcec5d78be511ea59984aee3499da5f3342
diff --git a/src/Juvix/Compiler/Core/Data/IdentDependencyInfo.hs b/src/Juvix/Compiler/Core/Data/IdentDependencyInfo.hs
index 063908ff3e..f70452518f 100644
--- a/src/Juvix/Compiler/Core/Data/IdentDependencyInfo.hs
+++ b/src/Juvix/Compiler/Core/Data/IdentDependencyInfo.hs
@@ -101,3 +101,6 @@ nonRecursiveIdents' tab =
   HashSet.difference
     (HashSet.fromList (HashMap.keys (tab ^. infoIdentifiers)))
     (recursiveIdentsClosure tab)
+
+nonRecursiveIdents :: Module -> HashSet Symbol
+nonRecursiveIdents = nonRecursiveIdents' . computeCombinedInfoTable
diff --git a/src/Juvix/Compiler/Core/Data/TransformationId.hs b/src/Juvix/Compiler/Core/Data/TransformationId.hs
index 3542f00418..f2d754696b 100644
--- a/src/Juvix/Compiler/Core/Data/TransformationId.hs
+++ b/src/Juvix/Compiler/Core/Data/TransformationId.hs
@@ -39,6 +39,7 @@ data TransformationId
   | SpecializeArgs
   | CaseFolding
   | CasePermutation
+  | ConstantFolding
   | FilterUnreachable
   | OptPhaseEval
   | OptPhaseExec
@@ -113,6 +114,7 @@ instance TransformationId' TransformationId where
     SpecializeArgs -> strSpecializeArgs
     CaseFolding -> strCaseFolding
     CasePermutation -> strCasePermutation
+    ConstantFolding -> strConstantFolding
     FilterUnreachable -> strFilterUnreachable
     OptPhaseEval -> strOptPhaseEval
     OptPhaseExec -> strOptPhaseExec
diff --git a/src/Juvix/Compiler/Core/Data/TransformationId/Strings.hs b/src/Juvix/Compiler/Core/Data/TransformationId/Strings.hs
index 7aaa71fae8..ac50840786 100644
--- a/src/Juvix/Compiler/Core/Data/TransformationId/Strings.hs
+++ b/src/Juvix/Compiler/Core/Data/TransformationId/Strings.hs
@@ -119,6 +119,9 @@ strCaseFolding = "case-folding"
 strCasePermutation :: Text
 strCasePermutation = "case-permutation"
 
+strConstantFolding :: Text
+strConstantFolding = "constant-folding"
+
 strFilterUnreachable :: Text
 strFilterUnreachable = "filter-unreachable"
 
diff --git a/src/Juvix/Compiler/Core/Transformation.hs b/src/Juvix/Compiler/Core/Transformation.hs
index d87e85f57e..f0a0a23764 100644
--- a/src/Juvix/Compiler/Core/Transformation.hs
+++ b/src/Juvix/Compiler/Core/Transformation.hs
@@ -36,6 +36,7 @@ import Juvix.Compiler.Core.Transformation.Normalize
 import Juvix.Compiler.Core.Transformation.Optimize.CaseCallLifting
 import Juvix.Compiler.Core.Transformation.Optimize.CaseFolding
 import Juvix.Compiler.Core.Transformation.Optimize.CasePermutation (casePermutation)
+import Juvix.Compiler.Core.Transformation.Optimize.ConstantFolding
 import Juvix.Compiler.Core.Transformation.Optimize.FilterUnreachable (filterUnreachable)
 import Juvix.Compiler.Core.Transformation.Optimize.Inlining
 import Juvix.Compiler.Core.Transformation.Optimize.LambdaFolding
@@ -96,6 +97,7 @@ applyTransformations ts tbl = foldM (flip appTrans) tbl ts
       SpecializeArgs -> return . specializeArgs
       CaseFolding -> return . caseFolding
       CasePermutation -> return . casePermutation
+      ConstantFolding -> constantFolding
       FilterUnreachable -> return . filterUnreachable
       OptPhaseEval -> Phase.Eval.optimize
       OptPhaseExec -> Phase.Exec.optimize
diff --git a/src/Juvix/Compiler/Core/Transformation/Optimize/Inlining.hs b/src/Juvix/Compiler/Core/Transformation/Optimize/Inlining.hs
index 9c54e4ac21..1dccadbff3 100644
--- a/src/Juvix/Compiler/Core/Transformation/Optimize/Inlining.hs
+++ b/src/Juvix/Compiler/Core/Transformation/Optimize/Inlining.hs
@@ -17,7 +17,7 @@ isInlineableLambda inlineDepth md bl node = case node of
     False
 
 convertNode :: Int -> HashSet Symbol -> Module -> Node -> Node
-convertNode inlineDepth recSyms md = dmapL go
+convertNode inlineDepth nonRecSyms md = dmapL go
   where
     go :: BinderList Binder -> Node -> Node
     go bl node = case node of
@@ -37,7 +37,7 @@ convertNode inlineDepth recSyms md = dmapL go
                   Just InlineNever ->
                     node
                   _
-                    | not (HashSet.member _identSymbol recSyms)
+                    | HashSet.member _identSymbol nonRecSyms
                         && isInlineableLambda inlineDepth md bl def
                         && length args >= argsNum ->
                         mkApps def args
@@ -57,7 +57,7 @@ convertNode inlineDepth recSyms md = dmapL go
           Just InlineAlways -> def
           Just InlineNever -> node
           _
-            | not (HashSet.member _identSymbol recSyms)
+            | HashSet.member _identSymbol nonRecSyms
                 && isImmediate md def ->
                 def
             | otherwise ->
@@ -76,7 +76,7 @@ convertNode inlineDepth recSyms md = dmapL go
                 Just InlineCase ->
                   NCase cs {_caseValue = mkApps def args}
                 Nothing
-                  | not (HashSet.member _identSymbol recSyms)
+                  | HashSet.member _identSymbol nonRecSyms
                       && isConstructorApp def
                       && checkDepth md bl inlineDepth def ->
                       NCase cs {_caseValue = mkApps def args}
@@ -92,9 +92,9 @@ convertNode inlineDepth recSyms md = dmapL go
         node
 
 inlining' :: Int -> HashSet Symbol -> Module -> Module
-inlining' inliningDepth recSyms md = mapT (const (convertNode inliningDepth recSyms md)) md
+inlining' inliningDepth nonRecSyms md = mapT (const (convertNode inliningDepth nonRecSyms md)) md
 
 inlining :: (Member (Reader CoreOptions) r) => Module -> Sem r Module
 inlining md = do
   d <- asks (^. optInliningDepth)
-  return $ inlining' d (recursiveIdents md) md
+  return $ inlining' d (nonRecursiveIdents md) md
diff --git a/src/Juvix/Compiler/Core/Transformation/Optimize/Phase/Main.hs b/src/Juvix/Compiler/Core/Transformation/Optimize/Phase/Main.hs
index 0c60f7fd4f..05a7cec3be 100644
--- a/src/Juvix/Compiler/Core/Transformation/Optimize/Phase/Main.hs
+++ b/src/Juvix/Compiler/Core/Transformation/Optimize/Phase/Main.hs
@@ -33,9 +33,6 @@ optimize' opts@CoreOptions {..} md =
     tab :: InfoTable
     tab = computeCombinedInfoTable md
 
-    recs :: HashSet Symbol
-    recs = recursiveIdents' tab
-
     nonRecs :: HashSet Symbol
     nonRecs = nonRecursiveIdents' tab
 
@@ -48,12 +45,12 @@ optimize' opts@CoreOptions {..} md =
           | otherwise = nonRecs
 
     doInlining :: Module -> Module
-    doInlining md' = inlining' _optInliningDepth recs' md'
+    doInlining md' = inlining' _optInliningDepth nonRecs' md'
       where
-        recs' =
+        nonRecs' =
           if
-              | _optOptimizationLevel > 1 -> recursiveIdents md'
-              | otherwise -> recs
+              | _optOptimizationLevel > 1 -> nonRecursiveIdents md'
+              | otherwise -> nonRecs
 
     doSimplification :: Int -> Module -> Module
     doSimplification n =
diff --git a/tests/Compilation/positive/test056.juvix b/tests/Compilation/positive/test056.juvix
index 2981ae3b5d..e7fb7b746a 100644
--- a/tests/Compilation/positive/test056.juvix
+++ b/tests/Compilation/positive/test056.juvix
@@ -9,20 +9,12 @@ mymap {A B} (f : A -> B) : List A -> List B
   | (x :: xs) := f x :: mymap f xs;
 
 {-# specialize: [2, 5], inline: false #-}
-myf
-  : {A B : Type}
-    -> A
-    -> (A -> A -> B)
-    -> A
-    -> B
-    -> Bool
-    -> B
+myf : {A B : Type} -> A -> (A -> A -> B) -> A -> B -> Bool -> B
   | a0 f a b true := f a0 a
   | a0 f a b false := b;
 
 {-# inline: false #-}
-myf'
-  : {A B : Type} -> A -> (A -> A -> A -> B) -> A -> B -> B
+myf' : {A B : Type} -> A -> (A -> A -> A -> B) -> A -> B -> B
   | a0 f a b := myf a0 (f a0) a b true;
 
 sum : List Nat -> Nat
@@ -40,8 +32,7 @@ funa : {A : Type} -> (A -> A) -> A -> A
 {-# specialize: true #-}
 type Additive A := mkAdditive {add : A -> A -> A};
 
-type Multiplicative A :=
-  mkMultiplicative {mul : A -> A -> A};
+type Multiplicative A := mkMultiplicative {mul : A -> A -> A};
 
 addNat : Additive Nat := mkAdditive (+);
 
@@ -49,20 +40,20 @@ addNat : Additive Nat := mkAdditive (+);
 mulNat : Multiplicative Nat := mkMultiplicative (*);
 
 {-# inline: false #-}
-fadd {A} (a : Additive A) (x y : A) : A :=
-  Additive.add a x y;
+fadd {A} (a : Additive A) (x y : A) : A := Additive.add a x y;
 
 {-# inline: false #-}
-fmul {A} (m : Multiplicative A) (x y : A) : A :=
-  Multiplicative.mul m x y;
+fmul {A} (m : Multiplicative A) (x y : A) : A := Multiplicative.mul m x y;
+
+{-# specialize: [1] #-}
+myfilter {A} (f : A → Bool) : List A → List A
+  | nil := nil
+  | (h :: hs) := ite (f h) (h :: myfilter f hs) (myfilter f hs);
 
 main : Nat :=
-  sum (mymap λ {x := x + 3} (1 :: 2 :: 3 :: 4 :: nil))
-    + sum
-      (flatten
-        (mymap
-          (mymap λ {x := x + 2})
-          ((1 :: nil) :: (2 :: 3 :: nil) :: nil)))
+  sum (myfilter (const false) [])
+    + sum (mymap λ {x := x + 3} (1 :: 2 :: 3 :: 4 :: nil))
+    + sum (flatten (mymap (mymap λ {x := x + 2}) ((1 :: nil) :: (2 :: 3 :: nil) :: nil)))
     + myf 3 (*) 2 5 true
     + myf 1 (+) 2 0 false
     + myf' 7 (const (+)) 2 0