diff --git a/mode.go b/mode.go
index 01d3444..a53aa7d 100644
--- a/mode.go
+++ b/mode.go
@@ -262,8 +262,10 @@ func ParseWithUmask(s string, umask uint) (Set, error) {
 			case 'w':
 				perm |= iWUser | iWGroup | iWOther
 			case 'X':
-				if op == '+' {
+				if op != '-' {
 					permX = iXUser | iXGroup | iXOther
+				} else {
+					perm |= iXUser | iXGroup | iXOther
 				}
 			case 'x':
 				perm |= iXUser | iXGroup | iXOther
diff --git a/mode_test.go b/mode_test.go
index c1c5f2b..dd51b4d 100644
--- a/mode_test.go
+++ b/mode_test.go
@@ -119,8 +119,8 @@ func TestApply(t *testing.T) {
 		{0777, 0333, 0000, "-r"},
 		{0777, 0555, 0000, "-w"},
 		{0777, 0666, 0000, "-x"},
-		{0777, 0777, 0000, "-X"},
-		{os.ModeDir | 0777, os.ModeDir | 0777, 0000, "-X"},
+		{0777, 0666, 0000, "-X"},
+		{os.ModeDir | 0777, os.ModeDir | 0666, 0000, "-X"},
 		{os.ModeSetuid | os.ModeSetgid | 0777, 0777, 0000, "-s"},
 		{0777, 0337, 0037, "-r"},
 		{0777, 0557, 0057, "-w"},
@@ -129,8 +129,8 @@ func TestApply(t *testing.T) {
 		{0777, 0377, 0000, "u-r"},
 		{0777, 0577, 0000, "u-w"},
 		{0777, 0677, 0000, "u-x"},
-		{0777, 0777, 0000, "u-X"},
-		{os.ModeDir | 0777, os.ModeDir | 0777, 0000, "u-X"},
+		{0777, 0677, 0000, "u-X"},
+		{os.ModeDir | 0777, os.ModeDir | 0677, 0000, "u-X"},
 		{os.ModeSetuid | 0777, 0777, 0000, "u-s"},
 
 		{0000, 0600, 0000, "u=rw"},
@@ -179,6 +179,15 @@ func TestApply(t *testing.T) {
 		{0670, 0644, 0000, "go=u-w"},
 		{0570, 0555, 0000, "go=u-w"},
 		{0370, 0311, 0000, "go=u-w"},
+
+		// Linux compatible X
+		{0444, 0644, 0000, "u=rwX,go=rX"},
+		{os.ModeDir | 0442, os.ModeDir | 0755, 0000, "u=rwX,go=rX"},
+		{0641, 0755, 0000, "u=rwX,go=rX"},
+		{0777, 0766, 0000, "go-X"},
+		{0424, 0000, 0000, "=X"},
+		{0421, 0111, 0000, "=X"},
+		{0421, 0555, 0000, "=rX"},
 	}
 	var lastSet Set
 	var lastStr string