diff --git a/invokeai/backend/flux/extensions/regional_prompting_extension.py b/invokeai/backend/flux/extensions/regional_prompting_extension.py
index c3eb8e542f..f5f203af69 100644
--- a/invokeai/backend/flux/extensions/regional_prompting_extension.py
+++ b/invokeai/backend/flux/extensions/regional_prompting_extension.py
@@ -154,24 +154,43 @@ class RegionalPromptingExtension:
                 t5_embedding_range.start : t5_embedding_range.end, t5_embedding_range.start : t5_embedding_range.end
             ] = 1.0
 
-            if image_mask is None:
-                continue
+            if image_mask is not None:
+                # 2. txt attends to corresponding regional img
+                # Note that we reshape to (1, img_seq_len) to ensure broadcasting works as desired.
+                regional_attention_mask[t5_embedding_range.start : t5_embedding_range.end, txt_seq_len:] = (
+                    image_mask.view(1, img_seq_len)
+                )
 
-            # 2. txt attends to corresponding regional img
-            # Note that we reshape to (1, img_seq_len) to ensure broadcasting works as desired.
-            regional_attention_mask[t5_embedding_range.start : t5_embedding_range.end, txt_seq_len:] = image_mask.view(
-                1, img_seq_len
-            )
+                # 3. regional img attends to corresponding txt
+                # Note that we reshape to (img_seq_len, 1) to ensure broadcasting works as desired.
+                regional_attention_mask[txt_seq_len:, t5_embedding_range.start : t5_embedding_range.end] = (
+                    image_mask.view(img_seq_len, 1)
+                )
 
-            # 3. regional img attends to corresponding txt
-            # Note that we reshape to (img_seq_len, 1) to ensure broadcasting works as desired.
-            regional_attention_mask[txt_seq_len:, t5_embedding_range.start : t5_embedding_range.end] = image_mask.view(
-                img_seq_len, 1
-            )
+                # 4. regional img attends to itself
+                image_mask = image_mask.view(img_seq_len, 1)
+                regional_attention_mask[txt_seq_len:, txt_seq_len:] += image_mask @ image_mask.T
+            else:
+                if background_region_mask is None:
+                    # There are no region masks, so we don't need to do anything here - this case is handled below.
+                    continue
 
-            # 4. regional img attends to itself
-            image_mask = image_mask.view(img_seq_len, 1)
-            regional_attention_mask[txt_seq_len:, txt_seq_len:] += image_mask @ image_mask.T
+                # We don't allow attention between non-background image regions and global prompts. This helps to ensure
+                # that regions focus on their local prompts. We do, however, allow attention between background regions
+                # and global prompts. If we didn't do this, then the background regions would not attend to any txt
+                # embeddings, which we found experimentally to cause artifacts.
+
+                # 2. global txt attends to background region
+                # Note that we reshape to (1, img_seq_len) to ensure broadcasting works as desired.
+                regional_attention_mask[t5_embedding_range.start : t5_embedding_range.end, txt_seq_len:] = (
+                    background_region_mask.view(1, img_seq_len)
+                )
+
+                # 3. background region attends to global txt
+                # Note that we reshape to (img_seq_len, 1) to ensure broadcasting works as desired.
+                regional_attention_mask[txt_seq_len:, t5_embedding_range.start : t5_embedding_range.end] = (
+                    background_region_mask.view(img_seq_len, 1)
+                )
 
         # Handle image background regions.
         if background_region_mask is None:
@@ -179,9 +198,9 @@ class RegionalPromptingExtension:
             regional_attention_mask[txt_seq_len:, :] = 1.0
             regional_attention_mask[:, txt_seq_len:] = 1.0
         else:
-            # Allow background regions to attend to themselves and to the entire txt embedding.
-            regional_attention_mask[txt_seq_len:, :] += background_region_mask.view(img_seq_len, 1)
-            regional_attention_mask[:, txt_seq_len:] += background_region_mask.view(1, img_seq_len)
+            # Allow background regions to attend to themselves.
+            regional_attention_mask[txt_seq_len:, txt_seq_len:] += background_region_mask.view(img_seq_len, 1)
+            regional_attention_mask[txt_seq_len:, txt_seq_len:] += background_region_mask.view(1, img_seq_len)
 
         # Convert attention mask to boolean.
         regional_attention_mask = regional_attention_mask > 0.5