diff --git a/lua/treesj/langs/nix.lua b/lua/treesj/langs/nix.lua
index 1149f27..f254d8a 100644
--- a/lua/treesj/langs/nix.lua
+++ b/lua/treesj/langs/nix.lua
@@ -4,7 +4,7 @@ return {
   list_expression = u.set_preset_for_list({
     both = {
       separator = '',
-    }
+    },
   }),
   attrset_expression = {
     target_nodes = { 'binding_set' },
@@ -18,7 +18,7 @@ return {
   }),
   formals = u.set_preset_for_args({
     both = {
-      omit = { 'formal', 'ellipses' }
+      omit = { 'formal', 'ellipses' },
     },
     split = {
       separator = '',
@@ -29,4 +29,18 @@ return {
       space_in_brackets = true,
     },
   }),
+  let_expression = u.set_default_preset({
+    both = {
+      omit = { 'binding_set' },
+    },
+    split = {
+      recursive = true,
+      inner_indent = 'normal',
+      last_indent = 'inner',
+    },
+    join = {
+      space_in_brackets = true,
+      space_separator = 1,
+    },
+  }),
 }
diff --git a/tests/langs/nix_spec.lua b/tests/langs/nix_spec.lua
index e61d4c3..841298c 100644
--- a/tests/langs/nix_spec.lua
+++ b/tests/langs/nix_spec.lua
@@ -34,6 +34,26 @@ local data_for_split = {
     result = { 30, 36 },
     settings = {},
   },
+  {
+    path = PATH,
+    mode = 'split',
+    lang = LANG,
+    desc = 'lang "%s", node "let_expression", preset default',
+    cursor = { 45, 6 },
+    expected = { 48, 53 },
+    result = { 44, 49 },
+    settings = {},
+  },
+  {
+    path = PATH,
+    mode = 'split',
+    lang = LANG,
+    desc = 'lang "%s", node "let_expression" with "attrset_expression", preset default',
+    cursor = { 57, 6 },
+    expected = { 60, 69 },
+    result = { 56, 65 },
+    settings = {},
+  },
 }
 
 local data_for_join = {
@@ -67,6 +87,26 @@ local data_for_join = {
     result = { 35, 36 },
     settings = {},
   },
+  {
+    path = PATH,
+    mode = 'join',
+    lang = LANG,
+    desc = 'lang "%s", node "let_expression", preset default',
+    cursor = { 49, 6 },
+    expected = { 44, 45 },
+    result = { 48, 49 },
+    settings = {},
+  },
+  {
+    path = PATH,
+    mode = 'join',
+    lang = LANG,
+    desc = 'lang "%s", node "let_expression" with "attrset_expression", preset default',
+    cursor = { 61, 6 },
+    expected = { 56, 57 },
+    result = { 60, 61 },
+    settings = {},
+  },
 }
 
 describe('TreeSJ SPLIT:', function()
diff --git a/tests/sample/index.nix b/tests/sample/index.nix
index 9475dab..41c8739 100644
--- a/tests/sample/index.nix
+++ b/tests/sample/index.nix
@@ -1,10 +1,10 @@
 { foo, ... }:
 {
   bar = [
-    # RESULT OF JOIN (nix "list_expression", preset default)
+    # RESULT OF JOIN (node "list_expression", preset default)
     [ 1 2 3 4 "a" "b" ]
 
-    # RESULT OF SPLIT (nix "list_expression", preset default)
+    # RESULT OF SPLIT (node "list_expression", preset default)
     [
       1
       2
@@ -14,10 +14,10 @@
       "b"
     ]
 
-    # RESULT OF JOIN (nix "binding_set", preset default)
+    # RESULT OF JOIN (node "binding_set", preset default)
     { a = 1; b = 2; c = "c"; }
 
-    # RESULT OF SPLIT (nix "binding_set", preset default)
+    # RESULT OF SPLIT (node "binding_set", preset default)
     {
       a = 1;
       b = 2;
@@ -26,12 +26,12 @@
 
   ];
 
-  # RESULT OF JOIN (nix "formals", preset default)
+  # RESULT OF JOIN (node "formals", preset default)
   func1 =
     { foo, bar, blub, ... }:
     { };
 
-  # RESULT OF SPLIT (nix "formals", preset default)
+  # RESULT OF SPLIT (node "formals", preset default)
   func2 =
     { foo
     , bar
@@ -39,4 +39,32 @@
     , ...
     }:
     { };
+
+  # RESULT OF JOIN (node "let_expression", preset default)
+  bla =
+    let x=1; y=2; in x + y;
+
+  # RESULT OF SPLIT (node "let_expression", preset default)
+  bla =
+    let
+      x=1;
+      y=2;
+    in
+    x + y;
+
+  # RESULT OF JOIN (node "let_expression" with "attrset_expression", preset default)
+  bla =
+    let x=1; y=2; in { a = 1; b = 2; c = "c"; };
+
+  # RESULT OF SPLIT (node "let_expression" with "attrset_expression", preset default)
+  bla =
+    let
+      x=1;
+      y=2;
+    in
+    {
+      a = 1;
+      b = 2;
+      c = "c";
+    };
 }