diff --git a/etienne-moqueur.cabal b/etienne-moqueur.cabal
index 6f4c496..27d4c7f 100644
--- a/etienne-moqueur.cabal
+++ b/etienne-moqueur.cabal
@@ -80,6 +80,7 @@ library
     , containers
     , hakyll
     , hashable
+    , megaparsec
     , mtl
     , split
     , text
@@ -106,6 +107,7 @@ executable etienne-moqueur-exe
     , etienne-moqueur
     , hakyll
     , hashable
+    , megaparsec
     , mtl
     , split
     , text
@@ -133,6 +135,7 @@ test-suite etienne-moqueur-test
     , etienne-moqueur
     , hakyll
     , hashable
+    , megaparsec
     , mtl
     , split
     , text
diff --git a/package.yaml b/package.yaml
index f1cf28e..ec3efaf 100644
--- a/package.yaml
+++ b/package.yaml
@@ -32,6 +32,7 @@ dependencies:
 - containers
 - hashable
 - split
+- megaparsec
 
 ghc-options:
 - -Wall
diff --git a/stack.yaml b/stack.yaml
index 5cff828..9994136 100644
--- a/stack.yaml
+++ b/stack.yaml
@@ -18,7 +18,7 @@
 # resolver: ./custom-snapshot.yaml
 # resolver: https://example.com/snapshots/2018-01-01.yaml
 resolver:
-  url: https://raw.githubusercontent.com/commercialhaskell/stackage-snapshots/master/lts/20/26.yaml
+  url: https://raw.githubusercontent.com/commercialhaskell/stackage-snapshots/master/lts/21/1.yaml
 
 # User packages to be built.
 # Various formats can be used as shown in the example below.
diff --git a/stack.yaml.lock b/stack.yaml.lock
index 47ea499..4a2b846 100644
--- a/stack.yaml.lock
+++ b/stack.yaml.lock
@@ -13,8 +13,8 @@ packages:
     hackage: clay-0.14.0@sha256:382eced24317f9ed0f7a0a4789cdfc6fc8dd32895cdb0c4ea50a1613bee08af3,2128
 snapshots:
 - completed:
-    sha256: 5a59b2a405b3aba3c00188453be172b85893cab8ebc352b1ef58b0eae5d248a2
-    size: 650475
-    url: https://raw.githubusercontent.com/commercialhaskell/stackage-snapshots/master/lts/20/26.yaml
+    sha256: c4381351ba5837a6356fcc0ebeb7a61fdcaf3a085c903a6f730f56b131d5cb58
+    size: 639143
+    url: https://raw.githubusercontent.com/commercialhaskell/stackage-snapshots/master/lts/21/1.yaml
   original:
-    url: https://raw.githubusercontent.com/commercialhaskell/stackage-snapshots/master/lts/20/26.yaml
+    url: https://raw.githubusercontent.com/commercialhaskell/stackage-snapshots/master/lts/21/1.yaml