diff --git a/src/asahi/layout/layout.c b/src/asahi/layout/layout.c
index 280466ed524..8ad7514c7e2 100644
--- a/src/asahi/layout/layout.c
+++ b/src/asahi/layout/layout.c
@@ -249,8 +249,12 @@ ail_make_miptree(struct ail_layout *layout)
     * allocate them all.
     */
    if (layout->levels > 1) {
-      layout->levels =
-         util_logbase2(MAX2(layout->width_px, layout->height_px)) + 1;
+      unsigned major_axis_px = MAX2(layout->width_px, layout->height_px);
+
+      if (layout->mipmapped_z)
+         major_axis_px = MAX2(major_axis_px, layout->depth_px);
+
+      layout->levels = util_logbase2(major_axis_px) + 1;
    }
 
    assert(util_format_get_blockdepth(layout->format) == 1 &&
diff --git a/src/asahi/layout/layout.h b/src/asahi/layout/layout.h
index d0d97a16fd1..fcb57cee8b2 100644
--- a/src/asahi/layout/layout.h
+++ b/src/asahi/layout/layout.h
@@ -79,6 +79,12 @@ struct ail_layout {
    /** Number of miplevels. 1 if no mipmapping is used. */
    uint8_t levels;
 
+   /** Should this image be mipmapped along the Z-axis in addition to the X- and
+    * Y-axes? This should be set for API-level 3D images, but not 2D arrays or
+    * cubes.
+    */
+   bool mipmapped_z;
+
    /** Tiling mode used */
    enum ail_tiling tiling;