diff --git a/build.zig b/build.zig
index 5fa6c2ed7..ae439db96 100644
--- a/build.zig
+++ b/build.zig
@@ -69,6 +69,10 @@ pub fn build(b: *std.build.Builder) !void {
 
     const wasm_target: WasmTarget = .browser;
 
+    // We use env vars throughout the build so we grab them immediately here.
+    var env = try std.process.getEnvMap(b.allocator);
+    defer env.deinit();
+
     tracy = b.option(
         bool,
         "tracy",
@@ -132,7 +136,6 @@ pub fn build(b: *std.build.Builder) !void {
 
         // If we're in a nix shell we default to doing this.
         // Note: we purposely never deinit envmap because we leak the strings
-        const env = try std.process.getEnvMap(b.allocator);
         if (env.get("IN_NIX_SHELL") == null) break :patch_rpath null;
         break :patch_rpath env.get("LD_LIBRARY_PATH");
     };
@@ -210,6 +213,41 @@ pub fn build(b: *std.build.Builder) !void {
         // Add the shared dependencies
         _ = try addDeps(b, exe, static);
 
+        // If we're in NixOS but not in the shell environment then we issue
+        // a warning because the rpath may not be setup properly.
+        const is_nixos = is_nixos: {
+            if (!target.isLinux()) break :is_nixos false;
+            if (!target.isNativeCpu()) break :is_nixos false;
+            if (target.getOsTag() != builtin.os.tag) break :is_nixos false;
+            break :is_nixos if (std.fs.accessAbsolute("/etc/NIXOS", .{})) true else |_| false;
+        };
+        if (is_nixos and env.get("IN_NIX_SHELL") == null) {
+            const notice = b.addLog(
+                "\x1b[" ++ color_map.get("yellow").? ++
+                    "\x1b[" ++ color_map.get("b").? ++
+                    "WARNING: " ++
+                    "\x1b[" ++ color_map.get("d").? ++
+                    \\Detected building on and for NixOS outside of the Nix shell enviornment.
+                    \\
+                    \\The resulting ghostty binary will likely fail on launch because it is
+                    \\unable to dynamically load the windowing libs (X11, Wayland, etc.).
+                    \\We highly recommend running only within the Nix build environment
+                    \\and the resulting binary will be portable across your system.
+                    \\
+                    \\To run in the Nix build environment, use the following command.
+                    \\Append any additional options like (`-Doptimize` flags). The resulting
+                    \\binary will be in zig-out as usual.
+                    \\
+                    \\  nix develop -c zig build
+                    \\
+                    ++
+                    "\x1b[0m",
+                .{},
+            );
+
+            exe.step.dependOn(&notice.step);
+        }
+
         // If we're installing, we get the install step so we can add
         // additional dependencies to it.
         const install_step = if (app_runtime != .none) step: {