diff --git a/stack.yaml b/stack.yaml
index 6cadf9c4..4c61c168 100644
--- a/stack.yaml
+++ b/stack.yaml
@@ -5,7 +5,10 @@ packages:
 extra-deps:
 - table-layout-0.9.1.0
 - data-default-instances-base-0.1.0.1
-- sequence-formats-1.8.1.0
+# - sequence-formats-1.8.1.1
+- /Users/stephan_schiffels/dev/sequence-formats
+# - git: https://github.com/stschiff/sequence-formats
+#   commit: d0ff76452b2df20ab49f651d587eca55e793130e
 - pipes-zlib-0.4.4.2
 - pipes-ordered-zip-1.2.1
 - co-log-0.6.0.2
diff --git a/stack.yaml.lock b/stack.yaml.lock
index cd66e887..4e58a5b7 100644
--- a/stack.yaml.lock
+++ b/stack.yaml.lock
@@ -18,13 +18,6 @@ packages:
       size: 242
   original:
     hackage: data-default-instances-base-0.1.0.1
-- completed:
-    hackage: sequence-formats-1.8.1.0@sha256:077b93e5c81295386901e0b022425f316075035ec5fe3f0e255a946bc8f1bfae,2984
-    pantry-tree:
-      sha256: a3084f8b105d9148c0379e7766a42851aea89455988c9a95668085964faf79b4
-      size: 2475
-  original:
-    hackage: sequence-formats-1.8.1.0
 - completed:
     hackage: pipes-zlib-0.4.4.2@sha256:eabd5aa29a030ecdeade80cfeb1787adc181bcf8fd378cb7b695b2af6cb26af6,1947
     pantry-tree: