diff --git a/SheepShaver/src/Unix/video_x.cpp b/SheepShaver/src/Unix/video_x.cpp
index a69e306b..4935326e 100644
--- a/SheepShaver/src/Unix/video_x.cpp
+++ b/SheepShaver/src/Unix/video_x.cpp
@@ -333,7 +333,7 @@ static bool open_display(void)
 			depth = 8;
 			break;
 		case APPLE_16_BIT:
-			depth = 16;
+			depth = xdepth == 15 ? 15 : 16;
 			break;
 		case APPLE_32_BIT:
 			depth = 32;