diff --git a/.gitmodules b/.gitmodules
index a26e9fceb..47328f4b1 100644
--- a/.gitmodules
+++ b/.gitmodules
@@ -25,3 +25,9 @@
 [submodule "external/gsasl-hs"]
 	path = external/gsasl-hs
 	url = https://github.com/Commelina/gsasl-hs.git
+[submodule "external/ghc-source-gen"]
+	path = external/ghc-source-gen
+	url = https://github.com/google/ghc-source-gen.git
+[submodule "external/proto-lens"]
+	path = external/proto-lens
+	url = https://github.com/4eUeP/proto-lens.git
diff --git a/cabal.project.ghc904 b/cabal.project.ghc904
new file mode 100644
index 000000000..64a975565
--- /dev/null
+++ b/cabal.project.ghc904
@@ -0,0 +1,79 @@
+with-compiler: ghc-9.4.8
+
+packages:
+  -- Waiting for new release
+  external/ghc-source-gen/ghc-source-gen.cabal
+  external/proto-lens/proto-lens-protobuf-types
+  external/proto-lens/proto-lens-runtime
+  external/proto-lens/proto-lens-protoc
+  external/proto-lens/proto-lens-setup
+  external/digest/digest.cabal
+
+  -- * External
+  external/proto3-wire/proto3-wire.cabal
+  external/proto3-suite/proto3-suite.cabal
+  external/hs-grpc/hs-grpc-server/hs-grpc-server.cabal
+  external/gRPC-haskell/grpc-haskell.cabal
+  external/gRPC-haskell/core/grpc-haskell-core.cabal
+  external/haskell-rocksdb-bindings
+  external/gsasl-hs/gsasl-hs.cabal
+
+  -- * Cpp library
+  common/api/cpp/hstream-api-cpp.cabal
+  clients/cpp/hstream-client-cpp.cabal
+
+  -- * HStream common
+  common/base/hstream-common-base.cabal
+  common/api/hstream-api-hs.cabal
+  common/hstream/hstream-common.cabal
+  common/stats/hstream-common-stats.cabal
+
+  hstream-store
+  common/server/hstream-common-server.cabal
+  hstream-diffflow
+  hstream-processing
+  hstream-sql
+  hstream-io
+  hstream-gossip
+  hstream-admin/server/hstream-admin-server.cabal
+  hstream-kafka
+  hstream
+  hstream-admin/hstream-admin.cabal
+
+package proto3-wire
+  tests: false
+
+package proto3-suite
+  tests: false
+
+package ghc-source-gen
+  tests: false
+
+package hs-grpc-server
+  flags: +hsgrpc_use_protosuite
+  tests: false
+
+package grpc-haskell
+  flags: +grpc_eliminate_insecure_build
+  tests: false
+
+package grpc-haskell-core
+  flags: +grpc_eliminate_insecure_build
+  tests: false
+
+package rocksdb-haskell-bindings
+  extra-include-dirs: /usr/local/include
+  extra-lib-dirs:     /usr/local/lib
+  tests: false
+
+constraints:
+    Z-Data      == 2.0.0.2
+  , zoovisitor  == 0.2.6.1
+  , criterion  ^>= 1.6
+  , aeson      ^>= 2.1
+
+  -- The following is needed to avoid breaking the build.
+  , blaze-textual == 0.2.1.0 || > 0.2.2.0
+  , entropy == 0.4.1.7 || > 0.4.1.9
+    -- https://github.com/nikita-volkov/deferred-folds/issues/6
+  , deferred-folds == 0.9.18.3 || > 0.9.18.4
diff --git a/external/ghc-source-gen b/external/ghc-source-gen
new file mode 160000
index 000000000..7527305ed
--- /dev/null
+++ b/external/ghc-source-gen
@@ -0,0 +1 @@
+Subproject commit 7527305ed59a47140053cf7bc87432fe1f8804d0
diff --git a/external/proto-lens b/external/proto-lens
new file mode 160000
index 000000000..073b75d99
--- /dev/null
+++ b/external/proto-lens
@@ -0,0 +1 @@
+Subproject commit 073b75d991531bfbd59beb2d612367699f699d82