diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index 8c3c95c25..57c851c1f 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -195,6 +195,7 @@ jobs:
       - name: Install FFI
         env:
           GITHUB_TOKEN: ${{ github.token }}
+          CURIO_OPTIMAL_LIBFILCRYPTO: 0
         run: |
           make deps
         shell: bash
@@ -230,7 +231,7 @@ jobs:
           echo "Using YugabyteDB Container IP: ${{env.CURIO_HARMONYDB_HOSTS}}"
           export CURIO_HARMONYDB_HOSTS=${{ env.CURIO_HARMONYDB_HOSTS }}
           export LOTUS_HARMONYDB_HOSTS=${{ env.CURIO_HARMONYDB_HOSTS }}
-          go test -v --tags=debug -timeout 30m ${{ matrix.test-suite.target }}
+          go test -v --tags="debug,fvm" -timeout 30m ${{ matrix.test-suite.target }}
 
       - name: Stop YugabyteDB container
         if: always()  # Ensure this runs even if the tests fail
diff --git a/Makefile b/Makefile
index 668089c46..88c77de1f 100644
--- a/Makefile
+++ b/Makefile
@@ -10,14 +10,31 @@ FFI_DEPS:=$(addprefix $(FFI_PATH),$(FFI_DEPS))
 
 $(FFI_DEPS): build/.filecoin-install ;
 
+# When enabled, build size-optimized libfilcrypto by default
+CURIO_OPTIMAL_LIBFILCRYPTO ?= 1
+
 build/.filecoin-install: $(FFI_PATH)
-	$(MAKE) -C $(FFI_PATH) $(FFI_DEPS:$(FFI_PATH)%=%)
+	@if [ "$(CURIO_OPTIMAL_LIBFILCRYPTO)" = "1" ]; then \
+		FFI_DISABLE_FVM=1 $(MAKE) curio-libfilecoin; \
+	else \
+		$(MAKE) -C $(FFI_PATH) $(FFI_DEPS:$(FFI_PATH)%=%); \
+	fi
 	@touch $@
 
 MODULES+=$(FFI_PATH)
 BUILD_DEPS+=build/.filecoin-install
 CLEAN+=build/.filecoin-install
 
+## Custom libfilcrypto build for Curio (size-optimized, no FVM)
+.PHONY: curio-libfilecoin
+curio-libfilecoin:
+	FFI_BUILD_FROM_SOURCE=1 \
+	FFI_USE_GPU=1 \
+	FFI_USE_MULTICORE_SDR=1 \
+	RUSTFLAGS='-C codegen-units=1 -C opt-level=3 -C strip=symbols' \
+	$(MAKE) -C $(FFI_PATH) clean .install-filcrypto
+	@echo "Rebuilt libfilcrypto for Curio (OpenCL+multicore, no default features)."
+
 ffi-version-check:
 	@[[ "$$(awk '/const Version/{print $$5}' extern/filecoin-ffi/version.go)" -eq 3 ]] || (echo "FFI version mismatch, update submodules"; exit 1)
 BUILD_DEPS+=ffi-version-check
@@ -82,6 +99,17 @@ CLEAN+=build/.update-modules
 deps: $(BUILD_DEPS)
 .PHONY: deps
 
+## Test targets
+
+test-deps: CURIO_OPTIMAL_LIBFILCRYPTO=0
+test-deps: $(BUILD_DEPS)
+	@echo "Built dependencies with FVM support for testing"
+.PHONY: test-deps
+
+test: test-deps
+	go test -v -tags="cgo,fvm" -timeout 30m ./itests/...
+.PHONY: test
+
 ## ldflags -s -w strips binary
 
 CURIO_TAGS ?= cunative
diff --git a/extern/filecoin-ffi b/extern/filecoin-ffi
index 586063e9c..377980587 160000
--- a/extern/filecoin-ffi
+++ b/extern/filecoin-ffi
@@ -1 +1 @@
-Subproject commit 586063e9cfa45147d554f176759520398715ba41
+Subproject commit 3779805870f9d070bb73a8083feef25c93be9c51