diff --git a/stack.yaml b/stack.yaml
index 8078abab..874987af 100644
--- a/stack.yaml
+++ b/stack.yaml
@@ -14,3 +14,6 @@ packages:
 - ./yesod
 - ./yesod-eventsource
 - ./yesod-websockets
+
+extra-deps:
+- attoparsec-aeson-2.1.0.0
diff --git a/stack.yaml.lock b/stack.yaml.lock
index 7940767f..4303539f 100644
--- a/stack.yaml.lock
+++ b/stack.yaml.lock
@@ -3,10 +3,17 @@
 # For more information, please see the documentation at:
 #   https://docs.haskellstack.org/en/stable/lock_files
 
-packages: []
+packages:
+- completed:
+    hackage: attoparsec-aeson-2.1.0.0@sha256:fa83aba43bfa58490de8f274d19b9d58b6403a207b12cac5f93922102b084c52,1154
+    pantry-tree:
+      sha256: 294c3a8a19a7ddad58097e18c624c6b34894b3c4a4cc490759cb31d842db242a
+      size: 114
+  original:
+    hackage: attoparsec-aeson-2.1.0.0
 snapshots:
 - completed:
+    sha256: 694573e96dca34db5636edb1fe6c96bb233ca0f9fb96c1ead1671cdfa9bd73e9
     size: 585603
     url: https://raw.githubusercontent.com/commercialhaskell/stackage-snapshots/master/lts/18/3.yaml
-    sha256: 694573e96dca34db5636edb1fe6c96bb233ca0f9fb96c1ead1671cdfa9bd73e9
   original: lts-18.3