diff --git a/internal/nix/install.go b/internal/nix/install.go
index d714b8b5646..cbc49c4c7bf 100644
--- a/internal/nix/install.go
+++ b/internal/nix/install.go
@@ -17,7 +17,6 @@ import (
 
 	"go.jetify.com/devbox/internal/boxcli/usererr"
 	"go.jetify.com/devbox/internal/cmdutil"
-	"go.jetify.com/devbox/internal/fileutil"
 	"go.jetify.com/devbox/nix"
 )
 
@@ -25,9 +24,33 @@ func BinaryInstalled() bool {
 	return cmdutil.Exists("nix")
 }
 
-func dirExistsAndIsNotEmpty(dir string) bool {
-	empty, err := fileutil.IsDirEmpty(dir)
-	return err == nil && !empty
+// nonNixDirEntries are directory entries that can appear inside /nix without
+// indicating an existing Nix installation. Container and VM users commonly
+// mount an otherwise-empty volume at /nix, and many filesystems (for example
+// ext4) create a lost+found directory at the root of such a mount. A /nix that
+// contains only these entries should still be treated as a fresh install
+// target rather than a broken installation.
+var nonNixDirEntries = map[string]bool{
+	"lost+found": true,
+	".DS_Store":  true,
+}
+
+// nixDirIsInstalled reports whether dir looks like it already contains a Nix
+// installation. It returns false when dir is missing, empty, or contains only
+// filesystem cruft (see nonNixDirEntries) so that Devbox installs Nix into a
+// freshly mounted /nix volume instead of reporting a broken installation.
+// See https://github.com/jetify-com/devbox/issues/2601.
+func nixDirIsInstalled(dir string) bool {
+	entries, err := os.ReadDir(dir)
+	if err != nil {
+		return false
+	}
+	for _, entry := range entries {
+		if !nonNixDirEntries[entry.Name()] {
+			return true
+		}
+	}
+	return false
 }
 
 var ensured = false
@@ -58,7 +81,7 @@ func EnsureNixInstalled(ctx context.Context, writer io.Writer, withDaemonFunc fu
 	if BinaryInstalled() {
 		return nil
 	}
-	if dirExistsAndIsNotEmpty("/nix") {
+	if nixDirIsInstalled("/nix") {
 		if _, err = SourceProfile(); err != nil {
 			return err
 		} else if BinaryInstalled() {
diff --git a/internal/nix/install_test.go b/internal/nix/install_test.go
index 7e8250849c3..99c17d56e50 100644
--- a/internal/nix/install_test.go
+++ b/internal/nix/install_test.go
@@ -12,7 +12,7 @@ import (
 	"github.com/stretchr/testify/require"
 )
 
-func TestDirExistsAndIsNotEmpty(t *testing.T) {
+func TestNixDirIsInstalled(t *testing.T) {
 	tests := []struct {
 		name     string
 		setup    func(string) error
@@ -34,10 +34,9 @@ func TestDirExistsAndIsNotEmpty(t *testing.T) {
 			expected: true,
 		},
 		{
-			name: "directory with subdirectories",
+			name: "directory with nix store",
 			setup: func(dir string) error {
-				subdir := filepath.Join(dir, "subdir")
-				return os.MkdirAll(subdir, 0o755)
+				return os.MkdirAll(filepath.Join(dir, "store"), 0o755)
 			},
 			expected: true,
 		},
@@ -49,6 +48,26 @@ func TestDirExistsAndIsNotEmpty(t *testing.T) {
 			},
 			expected: true,
 		},
+		{
+			// Regression test for jetify-com/devbox#2601: mounting an empty
+			// /nix volume in Docker/Kubernetes often leaves a lost+found
+			// directory, which must not be mistaken for an existing install.
+			name: "directory with only lost+found",
+			setup: func(dir string) error {
+				return os.MkdirAll(filepath.Join(dir, "lost+found"), 0o755)
+			},
+			expected: false,
+		},
+		{
+			name: "directory with lost+found and nix store",
+			setup: func(dir string) error {
+				if err := os.MkdirAll(filepath.Join(dir, "lost+found"), 0o755); err != nil {
+					return err
+				}
+				return os.MkdirAll(filepath.Join(dir, "store"), 0o755)
+			},
+			expected: true,
+		},
 		{
 			name: "non-existent directory",
 			setup: func(dir string) error {
@@ -70,7 +89,7 @@ func TestDirExistsAndIsNotEmpty(t *testing.T) {
 			}
 
 			// Run the function
-			result := dirExistsAndIsNotEmpty(tempDir)
+			result := nixDirIsInstalled(tempDir)
 
 			// Check results
 			assert.Equal(t, curTest.expected, result)