diff --git a/src/posix/cocoa/i_main.mm b/src/posix/cocoa/i_main.mm
index 1c418b91b..0b49a6d21 100644
--- a/src/posix/cocoa/i_main.mm
+++ b/src/posix/cocoa/i_main.mm
@@ -156,6 +156,7 @@ static void I_DetectOS()
 		case 10: name = "OS X Yosemite";         break;
 		case 11: name = "OS X El Capitan";       break;
 		case 12: name = "macOS Sierra";          break;
+		case 13: name = "macOS High Sierra";     break;
 	}
 
 	char release[16] = "unknown";