diff --git a/CHANGELOG.md b/CHANGELOG.md
index bdec3fb..278fbe7 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -14,6 +14,10 @@ Activate / deactivate layer opacity according to prefix
 Activate / deactivate all masks using MA layers
 -->
 
+1.8.5
+
+- changed: `group adjacent prefix` prefix pattern now ignore case
+
 1.8.4
 
 - fix: select node from layer
diff --git a/__init__.py b/__init__.py
index 7f1e5e2..91c5317 100644
--- a/__init__.py
+++ b/__init__.py
@@ -2,7 +2,7 @@ bl_info = {
     "name": "GP Render",
     "description": "Organise export of gp layers through compositor output",
     "author": "Samuel Bernou",
-    "version": (1, 8, 4),
+    "version": (1, 8, 5),
     "blender": (3, 0, 0),
     "location": "View3D",
     "warning": "",
diff --git a/fn.py b/fn.py
index 750e39d..16e824f 100644
--- a/fn.py
+++ b/fn.py
@@ -591,7 +591,7 @@ def group_adjacent_layer_prefix_rlayer(ob, excluded_prefix=[], first_name=True):
     '''
 
     pattern = os.environ.get('GP_RENDER_MERGE_PATTERN', r'^([A-Z]{2})_')
-    re_prefix = re.compile(pattern)
+    re_prefix = re.compile(pattern, flags=re.IGNORECASE)
 
     if isinstance(excluded_prefix, str):
         excluded_prefix = [p.strip() for p in excluded_prefix.split(',')]