diff --git a/flake.lock b/flake.lock
index 656ebe7..b2d1a6c 100644
--- a/flake.lock
+++ b/flake.lock
@@ -36,11 +36,11 @@
     },
     "nixpkgs": {
       "locked": {
-        "lastModified": 1740162160,
-        "narHash": "sha256-SSYxFhqCOb3aiPb6MmN68yEzBIltfom8IgRz7phHscM=",
+        "lastModified": 1741862977,
+        "narHash": "sha256-prZ0M8vE/ghRGGZcflvxCu40ObKaB+ikn74/xQoNrGQ=",
         "owner": "nixos",
         "repo": "nixpkgs",
-        "rev": "11415c7ae8539d6292f2928317ee7a8410b28bb9",
+        "rev": "cdd2ef009676ac92b715ff26630164bb88fec4e0",
         "type": "github"
       },
       "original": {
diff --git a/flake.nix b/flake.nix
index 0f10af9..1df5f6b 100644
--- a/flake.nix
+++ b/flake.nix
@@ -26,14 +26,14 @@
       system:
       let
         pkgs = nixpkgs.legacyPackages.${system};
-        version = "0.3.0";
+        version = "0.4.0";
       in
       {
         packages.workon = pkgs.buildGoModule {
           pname = "workon";
           version = version;
           src = ./.;
-          vendorHash = "sha256-HLjR2041wlhOzfKG6PQe5/DVfAEAX6O7/jd2E/lJ43E=";
+          vendorHash = "sha256-p3bwgNUbUsgJfANIOxG/+GXeh2/OddxYs0EK3JfnD4s=";
 
           ldflags = [
             "-s -w -X github.com/walkah/workon/cmd.version=${version}"
diff --git a/go.mod b/go.mod
index f022360..3501e26 100644
--- a/go.mod
+++ b/go.mod
@@ -26,9 +26,9 @@ require (
 	github.com/spf13/pflag v1.0.6 // indirect
 	github.com/subosito/gotenv v1.6.0 // indirect
 	go.uber.org/multierr v1.11.0 // indirect
-	golang.org/x/exp v0.0.0-20250218142911-aa4b98e5adaa // indirect
-	golang.org/x/sys v0.30.0 // indirect
-	golang.org/x/text v0.22.0 // indirect
+	golang.org/x/exp v0.0.0-20250305212735-054e65f0b394 // indirect
+	golang.org/x/sys v0.31.0 // indirect
+	golang.org/x/text v0.23.0 // indirect
 	gopkg.in/ini.v1 v1.67.0 // indirect
 	gopkg.in/yaml.v3 v3.0.1 // indirect
 )
diff --git a/go.sum b/go.sum
index 8d567f5..ab8d6f5 100644
--- a/go.sum
+++ b/go.sum
@@ -66,14 +66,20 @@ golang.org/x/exp v0.0.0-20241210194714-1829a127f884 h1:Y/Mj/94zIQQGHVSv1tTtQBDaQ
 golang.org/x/exp v0.0.0-20241210194714-1829a127f884/go.mod h1:qj5a5QZpwLU2NLQudwIN5koi3beDhSAlJwa67PuM98c=
 golang.org/x/exp v0.0.0-20250218142911-aa4b98e5adaa h1:t2QcU6V556bFjYgu4L6C+6VrCPyJZ+eyRsABUPs1mz4=
 golang.org/x/exp v0.0.0-20250218142911-aa4b98e5adaa/go.mod h1:BHOTPb3L19zxehTsLoJXVaTktb06DFgmdW6Wb9s8jqk=
+golang.org/x/exp v0.0.0-20250305212735-054e65f0b394 h1:nDVHiLt8aIbd/VzvPWN6kSOPE7+F/fNFDSXLVYkE/Iw=
+golang.org/x/exp v0.0.0-20250305212735-054e65f0b394/go.mod h1:sIifuuw/Yco/y6yb6+bDNfyeQ/MdPUy/hKEMYQV17cM=
 golang.org/x/sys v0.28.0 h1:Fksou7UEQUWlKvIdsqzJmUmCX3cZuD2+P3XyyzwMhlA=
 golang.org/x/sys v0.28.0/go.mod h1:/VUhepiaJMQUp4+oa/7Zr1D23ma6VTLIYjOOTFZPUcA=
 golang.org/x/sys v0.30.0 h1:QjkSwP/36a20jFYWkSue1YwXzLmsV5Gfq7Eiy72C1uc=
 golang.org/x/sys v0.30.0/go.mod h1:/VUhepiaJMQUp4+oa/7Zr1D23ma6VTLIYjOOTFZPUcA=
+golang.org/x/sys v0.31.0 h1:ioabZlmFYtWhL+TRYpcnNlLwhyxaM9kWTDEmfnprqik=
+golang.org/x/sys v0.31.0/go.mod h1:BJP2sWEmIv4KK5OTEluFJCKSidICx8ciO85XgH3Ak8k=
 golang.org/x/text v0.21.0 h1:zyQAAkrwaneQ066sspRyJaG9VNi/YJ1NfzcGB3hZ/qo=
 golang.org/x/text v0.21.0/go.mod h1:4IBbMaMmOPCJ8SecivzSH54+73PCFmPWxNTLm+vZkEQ=
 golang.org/x/text v0.22.0 h1:bofq7m3/HAFvbF51jz3Q9wLg3jkvSPuiZu/pD1XwgtM=
 golang.org/x/text v0.22.0/go.mod h1:YRoo4H8PVmsu+E3Ou7cqLVH8oXWIHVoX0jqUWALQhfY=
+golang.org/x/text v0.23.0 h1:D71I7dUrlY+VX0gQShAThNGHFxZ13dGLBHQLVl1mJlY=
+golang.org/x/text v0.23.0/go.mod h1:/BLNzu4aZCJ1+kcD0DNRotWKage4q2rGVAg4o22unh4=
 gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405/go.mod h1:Co6ibVJAznAaIkqp8huTwlJQCZ016jof/cbN4VW5Yz0=
 gopkg.in/check.v1 v1.0.0-20190902080502-41f04d3bba15 h1:YR8cESwS4TdDjEe65xsg0ogRM/Nc3DYOhEAlW+xobZo=
 gopkg.in/check.v1 v1.0.0-20190902080502-41f04d3bba15/go.mod h1:Co6ibVJAznAaIkqp8huTwlJQCZ016jof/cbN4VW5Yz0=
diff --git a/tmux/project.go b/tmux/project.go
index a5d4541..045d4ad 100644
--- a/tmux/project.go
+++ b/tmux/project.go
@@ -15,11 +15,12 @@ import (
 )
 
 type Project struct {
-	Name           string   `yaml:"name"`
-	Root           string   `yaml:"root"`
-	OnProjectStart []string `yaml:"on_project_start,omitempty"`
-	OnProjectStop  []string `yaml:"on_project_stop,omitempty"`
-	Windows        []Window `yaml:"windows"`
+	Name           string            `yaml:"name"`
+	Root           string            `yaml:"root"`
+	Environment    map[string]string `yaml:"environment"`
+	OnProjectStart []string          `yaml:"on_project_start,omitempty"`
+	OnProjectStop  []string          `yaml:"on_project_stop,omitempty"`
+	Windows        []Window          `yaml:"windows"`
 }
 
 func StartProject(name string) {
@@ -36,6 +37,8 @@ func StartProject(name string) {
 		p.RunCommands(p.OnProjectStart)
 
 		tmux.Run("new-session", "-d", "-s", name, "-n", p.Windows[0].Name, "-c", p.Windows[0].Root)
+
+		p.SetEnvironment(tmux, name, p.Environment)
 		for index, window := range p.Windows {
 			if index > 0 {
 				window.Create(tmux)
@@ -217,6 +220,12 @@ func (p *Project) RunCommands(commands []string) {
 	}
 }
 
+func (p *Project) SetEnvironment(tmux *Tmux, target string, environment map[string]string) {
+	for key, value := range environment {
+		tmux.Run("setenv", "-t", target, key, value)
+	}
+}
+
 func getConfigDir() string {
 	home, _ := homedir.Dir()
 	return path.Join(home, ".workon")