diff --git a/.github/workflows/haskell-ci.yml b/.github/workflows/haskell-ci.yml
index 61ba09d9..ea7004c4 100644
--- a/.github/workflows/haskell-ci.yml
+++ b/.github/workflows/haskell-ci.yml
@@ -42,9 +42,9 @@ jobs:
             compilerVersion: 9.8.2
             setup-method: ghcup
             allow-failure: false
-          - compiler: ghc-9.6.4
+          - compiler: ghc-9.6.6
             compilerKind: ghc
-            compilerVersion: 9.6.4
+            compilerVersion: 9.6.6
             setup-method: ghcup
             allow-failure: false
           - compiler: ghc-9.4.8
diff --git a/grapesy/grapesy.cabal b/grapesy/grapesy.cabal
index 46230f9f..1019a58b 100644
--- a/grapesy/grapesy.cabal
+++ b/grapesy/grapesy.cabal
@@ -22,7 +22,7 @@ data-files:         route_guide_db.json
 tested-with:        GHC==8.10.7
                   , GHC==9.2.8
                   , GHC==9.4.8
-                  , GHC==9.6.4
+                  , GHC==9.6.6
                   , GHC==9.8.2
                   , GHC==9.10.1
 
diff --git a/grpc-spec/grpc-spec.cabal b/grpc-spec/grpc-spec.cabal
index d343f743..21df49fe 100644
--- a/grpc-spec/grpc-spec.cabal
+++ b/grpc-spec/grpc-spec.cabal
@@ -17,7 +17,7 @@ extra-doc-files:    CHANGELOG.md
 tested-with:        GHC==8.10.7
                   , GHC==9.2.8
                   , GHC==9.4.8
-                  , GHC==9.6.4
+                  , GHC==9.6.6
                   , GHC==9.8.2
                   , GHC==9.10.1
 
diff --git a/tutorials/basics/basics.cabal b/tutorials/basics/basics.cabal
index 5aa86751..da232a5a 100644
--- a/tutorials/basics/basics.cabal
+++ b/tutorials/basics/basics.cabal
@@ -13,7 +13,7 @@ data-files:         route_guide_db.json
 tested-with:        GHC==8.10.7
                   , GHC==9.2.8
                   , GHC==9.4.8
-                  , GHC==9.6.4
+                  , GHC==9.6.6
                   , GHC==9.8.2
 
 custom-setup
diff --git a/tutorials/lowlevel/lowlevel.cabal b/tutorials/lowlevel/lowlevel.cabal
index d62854fe..0920a640 100644
--- a/tutorials/lowlevel/lowlevel.cabal
+++ b/tutorials/lowlevel/lowlevel.cabal
@@ -13,7 +13,7 @@ data-files:         route_guide_db.json
 tested-with:        GHC==8.10.7
                   , GHC==9.2.8
                   , GHC==9.4.8
-                  , GHC==9.6.4
+                  , GHC==9.6.6
                   , GHC==9.8.2
 
 custom-setup
diff --git a/tutorials/metadata/metadata.cabal b/tutorials/metadata/metadata.cabal
index c96030ed..336dec45 100644
--- a/tutorials/metadata/metadata.cabal
+++ b/tutorials/metadata/metadata.cabal
@@ -11,7 +11,7 @@ extra-source-files: proto/fileserver.proto
 tested-with:        GHC==8.10.7
                   , GHC==9.2.8
                   , GHC==9.4.8
-                  , GHC==9.6.4
+                  , GHC==9.6.6
                   , GHC==9.8.2
 
 custom-setup
diff --git a/tutorials/quickstart/quickstart.cabal b/tutorials/quickstart/quickstart.cabal
index 7ce86388..ae4a51a5 100644
--- a/tutorials/quickstart/quickstart.cabal
+++ b/tutorials/quickstart/quickstart.cabal
@@ -11,7 +11,7 @@ extra-source-files: proto/helloworld.proto
 tested-with:        GHC==8.10.7
                   , GHC==9.2.8
                   , GHC==9.4.8
-                  , GHC==9.6.4
+                  , GHC==9.6.6
                   , GHC==9.8.2
 
 custom-setup