--- a/src/backend/renderer/gles/mod.rs
+++ b/src/backend/renderer/gles/mod.rs
@@ -883,6 +883,8 @@
         // why not store a `GlesTexture`? because the user might do so.
         // this is guaranteed a non-public internal type, so we are good.
         type CacheMap = HashMap<ContextId<GlesTexture>, Arc<GlesTextureInternal>>;
+        static SHM_FORMAT_CHANGE_LOGS: std::sync::atomic::AtomicUsize =
+            std::sync::atomic::AtomicUsize::new(0);
 
         let mut surface_lock = surface.as_ref().map(|surface_data| {
             surface_data
@@ -937,7 +939,33 @@
                 surface_lock
                     .as_ref()
                     .and_then(|cache| cache.get(&id).cloned())
-                    .filter(|texture| texture.size == (width, height).into())
+                    .filter(|texture| {
+                        let format_matches =
+                            texture.format == Some(internal_format) && texture.has_alpha == has_alpha;
+                        if !format_matches
+                            && tracing::enabled!(tracing::Level::DEBUG)
+                            && SHM_FORMAT_CHANGE_LOGS
+                                .fetch_update(
+                                    std::sync::atomic::Ordering::Relaxed,
+                                    std::sync::atomic::Ordering::Relaxed,
+                                    |count| (count < 16).then_some(count + 1),
+                                )
+                                .is_ok()
+                        {
+                            tracing::debug!(
+                                old_width = texture.size.w,
+                                old_height = texture.size.h,
+                                new_width = width,
+                                new_height = height,
+                                old_internal_format = texture.format.unwrap_or(0),
+                                new_internal_format = internal_format,
+                                old_has_alpha = texture.has_alpha,
+                                new_has_alpha = has_alpha,
+                                "SHM texture cache format changed"
+                            );
+                        }
+                        texture.size == (width, height).into() && format_matches
+                    })
                     .unwrap_or_else(|| {
                         let mut tex = 0;
                         unsafe { self.gl.GenTextures(1, &mut tex) };