diff --git a/Makefile b/Makefile
index 1d0648c4..a7ce65c1 100644
--- a/Makefile
+++ b/Makefile
@@ -36,7 +36,6 @@ COVERAGE_PATH := $(BUILD_PATH)/coverage
 
 PROTOBUF_VERSION = 3.20.1
 PROTO_SOURCES = $(shell find pkg -name '*.proto' | grep -v /vendor/)
-PROTO_GOFILES = $(patsubst %.proto,%.pb.go,$(PROTO_SOURCES))
 PROTO_INCLUDE = -I $(PWD) -I$(PROTOC_PATH)/include
 PROTO_OPTIONS = --proto_path=. $(PROTO_INCLUDE) \
     --go_opt=paths=source_relative --go_out=. \
@@ -80,11 +79,15 @@ FORCE:
 # build targets
 #
 
-build-proto: check-protoc install-ttrpc-plugin install-wasm-plugin install-protoc-dependencies $(PROTO_GOFILES)
+build-proto: check-protoc install-ttrpc-plugin install-wasm-plugin install-protoc-dependencies
+	for src in $(PROTO_SOURCES); do \
+		$(PROTO_COMPILE) $$src; \
+	done
+	sed -i '1s;^;//go:build !wasip1\n\n;' pkg/api/api_ttrpc.pb.go
 
 .PHONY: build-proto-dockerized
 build-proto-dockerized:
-	$(Q)docker build --build-arg ARTIFACTS="$(dir $(PROTO_GOFILES))" --target final \
+	$(Q)docker build --build-arg ARTIFACTS="$(dir $(PROTO_SOURCES))" --target final \
 		--output type=local,dest=$(RESOLVED_PWD) \
 		-f hack/Dockerfile.buildproto .
 	$(Q)tar xf artifacts.tgz && rm -f artifacts.tgz
@@ -176,15 +179,6 @@ validate-repo-no-changes:
 		exit 1; \
 	}
 
-#
-# proto generation targets
-#
-
-%.pb.go: %.proto
-	$(Q)echo "Generating $@..."; \
-	$(PROTO_COMPILE) $<
-	sed -i '1s;^;//go:build !wasip1\n\n;' pkg/api/api_ttrpc.pb.go
-
 #
 # targets for installing dependencies
 #
@@ -199,7 +193,7 @@ check-protoc:
 	fi
 
 install-protoc install-protobuf:
-	$(Q)PROTOBUF_VERSION=$(PROTOBUF_VERSION) ./scripts/install-protobuf
+	$(Q)PROTOBUF_VERSION=$(PROTOBUF_VERSION) INSTALL_DIR=$(PROTOC_PATH) ./scripts/install-protobuf
 
 clean-protoc:
 	$(Q)rm -rf $(PROTOC_PATH)
diff --git a/hack/Dockerfile.buildproto b/hack/Dockerfile.buildproto
index 11049a05..2c2a2ba7 100644
--- a/hack/Dockerfile.buildproto
+++ b/hack/Dockerfile.buildproto
@@ -23,12 +23,9 @@ WORKDIR /go/src
 RUN apt-get update && apt-get install -y unzip
 
 RUN --mount=type=cache,target=/go/pkg/mod/ \
-    --mount=src=.,target=. \
-    make install-protoc-dependencies install-ttrpc-plugin install-wasm-plugin install-protoc
-
-RUN --mount=type=cache,target=/go/pkg/mod/ \
+    --mount=type=cache,target=/go/tools/,sharing=private \
     --mount=src=.,target=.,rw=true \
-    make build-proto && \
+    make build-proto PROTOC_PATH=/go/tools/protoc && \
     tar czf /artifacts.tgz ${ARTIFACTS}
 
 FROM scratch AS final
diff --git a/scripts/install-protobuf b/scripts/install-protobuf
index 4ab3023b..2f02ee5c 100755
--- a/scripts/install-protobuf
+++ b/scripts/install-protobuf
@@ -24,7 +24,7 @@ PROTOBUF_VERSION=${PROTOBUF_VERSION-3.20.1}
 GOARCH=$(go env GOARCH)
 GOOS=$(go env GOOS)
 PROTOBUF_DIR=$(mktemp -d)
-INSTALL_DIR="$PWD/build/tools/protoc"
+INSTALL_DIR=${INSTALL_DIR-"$PWD/build/tools/protoc"}
 
 mkdir -p "$INSTALL_DIR"