diff --git a/CHANGELOG.md b/CHANGELOG.md
index af7fe73a..cfbbde53 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -82,6 +82,10 @@
 ### Deprecated
 ### Removed
 ### Fixed
+
+* 10-bit surfaces sometimes used instead of 16-bit.
+
+
 ### Security
 ### Contributors
 
diff --git a/shm.c b/shm.c
index b586b504..4680c12c 100644
--- a/shm.c
+++ b/shm.c
@@ -994,7 +994,7 @@ shm_chain_new(struct wayland *wayl, bool scrollable, size_t pix_instances,
             pixman_fmt_without_alpha = PIXMAN_a16b16g16r16;
             shm_fmt_without_alpha = WL_SHM_FORMAT_XBGR16161616;
 
-            pixman_fmt_without_alpha = PIXMAN_a16b16g16r16;
+            pixman_fmt_with_alpha = PIXMAN_a16b16g16r16;
             shm_fmt_with_alpha = WL_SHM_FORMAT_ABGR16161616;
 
             if (!have_logged) {