diff --git a/examples/grenade-examples.cabal b/examples/grenade-examples.cabal
index f0e3f84..9db0f73 100644
--- a/examples/grenade-examples.cabal
+++ b/examples/grenade-examples.cabal
@@ -26,7 +26,7 @@ executable             feedforward
                      , bytestring
                      , cereal
                      , either
-                     , optparse-applicative            >= 0.13       && < 0.16
+                     , optparse-applicative            >= 0.13       && < 0.17
                      , text                            == 1.2.*
                      , mtl                             >= 2.2.1      && < 2.3
                      , hmatrix
@@ -42,7 +42,7 @@ executable             mnist
                      , grenade
                      , attoparsec
                      , either
-                     , optparse-applicative            >= 0.13       && < 0.16
+                     , optparse-applicative            >= 0.13       && < 0.17
                      , text                            == 1.2.*
                      , mtl                             >= 2.2.1      && < 2.3
                      , hmatrix                         >= 0.18       && < 0.21
@@ -61,7 +61,7 @@ executable             gan-mnist
                      , bytestring
                      , cereal
                      , either
-                     , optparse-applicative            >= 0.13       && < 0.16
+                     , optparse-applicative            >= 0.13       && < 0.17
                      , text                            == 1.2.*
                      , mtl                             >= 2.2.1      && < 2.3
                      , hmatrix                         >= 0.18       && < 0.21
@@ -78,7 +78,7 @@ executable             recurrent
                      , grenade
                      , attoparsec
                      , either
-                     , optparse-applicative            >= 0.13       && < 0.16
+                     , optparse-applicative            >= 0.13       && < 0.17
                      , text                            == 1.2.*
                      , mtl                             >= 2.2.1      && < 2.3
                      , hmatrix                         >= 0.18       && < 0.21
@@ -96,7 +96,7 @@ executable             shakespeare
                      , bytestring
                      , cereal
                      , either
-                     , optparse-applicative            >= 0.13       && < 0.16
+                     , optparse-applicative            >= 0.13       && < 0.17
                      , text                            == 1.2.*
                      , mtl                             >= 2.2.1      && < 2.3
                      , hmatrix                         >= 0.18       && < 0.21
diff --git a/stack.yaml b/stack.yaml
index cf4cd48..e147d58 100644
--- a/stack.yaml
+++ b/stack.yaml
@@ -20,7 +20,7 @@
 #
 # resolver: ./custom-snapshot.yaml
 # resolver: https://example.com/snapshots/2018-01-01.yaml
-resolver: lts-15.5
+resolver: lts-18.28
 
 # 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 0e3185b..15158f9 100644
--- a/stack.yaml.lock
+++ b/stack.yaml.lock
@@ -13,7 +13,7 @@ packages:
     hackage: typelits-witnesses-0.3.0.3
 snapshots:
 - completed:
-    size: 491372
-    url: https://raw.githubusercontent.com/commercialhaskell/stackage-snapshots/master/lts/15/5.yaml
-    sha256: 1b549cfff328040c382a70a84a2087aac8dab6d778bf92f32a93a771a1980dfc
-  original: lts-15.5
+    size: 590100
+    url: https://raw.githubusercontent.com/commercialhaskell/stackage-snapshots/master/lts/18/28.yaml
+    sha256: 428ec8d5ce932190d3cbe266b9eb3c175cd81e984babf876b64019e2cbe4ea68
+  original: lts-18.28