diff --git a/Makefile b/Makefile
index c15f53566..a1ae82179 100644
--- a/Makefile
+++ b/Makefile
@@ -17,6 +17,7 @@ FAST_TESTS?=FALSE
 FAST_BENCH?=FALSE
 BENCH_OP_FLAVOR?=DEFAULT
 NODE_VERSION=20
+FORWARD_COMPAT?=OFF
 # sed: -n, do not print input stream, -e means a script/expression
 # 1,/version/ indicates from the first line, to the line matching version at the start of the line
 # p indicates to print, so we keep only the start of the Cargo.toml until we hit the first version
@@ -49,6 +50,12 @@ else
 		COVERAGE_ONLY=
 endif
 
+ifeq ($(FORWARD_COMPAT),ON)
+		FORWARD_COMPAT_FEATURE=forward_compatibility
+else
+		FORWARD_COMPAT_FEATURE=
+endif
+
 # Variables used only for regex_engine example
 REGEX_STRING?=''
 REGEX_PATTERN?=''
@@ -286,15 +293,16 @@ symlink_c_libs_without_fingerprint:
 .PHONY: build_c_api # Build the C API for boolean, shortint and integer
 build_c_api: install_rs_check_toolchain
 	RUSTFLAGS="$(RUSTFLAGS)" cargo $(CARGO_RS_CHECK_TOOLCHAIN) build --profile $(CARGO_PROFILE) \
-		--features=$(TARGET_ARCH_FEATURE),boolean-c-api,shortint-c-api,high-level-c-api \
+		--features=$(TARGET_ARCH_FEATURE),boolean-c-api,shortint-c-api,high-level-c-api,$(FORWARD_COMPAT_FEATURE) \
 		-p $(TFHE_SPEC)
 	@"$(MAKE)" symlink_c_libs_without_fingerprint
 
 .PHONY: build_c_api_experimental_deterministic_fft # Build the C API for boolean, shortint and integer with experimental deterministic FFT
 build_c_api_experimental_deterministic_fft: install_rs_check_toolchain
 	RUSTFLAGS="$(RUSTFLAGS)" cargo $(CARGO_RS_CHECK_TOOLCHAIN) build --profile $(CARGO_PROFILE) \
-		--features=$(TARGET_ARCH_FEATURE),boolean-c-api,shortint-c-api,high-level-c-api,experimental-force_fft_algo_dif4 \
+		--features=$(TARGET_ARCH_FEATURE),boolean-c-api,shortint-c-api,high-level-c-api,experimental-force_fft_algo_dif4,$(FORWARD_COMPAT_FEATURE) \
 		-p $(TFHE_SPEC)
+	@"$(MAKE)" symlink_c_libs_without_fingerprint
 
 .PHONY: build_web_js_api # Build the js API targeting the web browser
 build_web_js_api: install_rs_build_toolchain install_wasm_pack
@@ -397,14 +405,14 @@ test_shortint_ci: install_rs_build_toolchain install_cargo_nextest
 	BIG_TESTS_INSTANCE="$(BIG_TESTS_INSTANCE)" \
 	FAST_TESTS="$(FAST_TESTS)" \
 		./scripts/shortint-tests.sh --rust-toolchain $(CARGO_RS_BUILD_TOOLCHAIN) \
-		--cargo-profile "$(CARGO_PROFILE)"
+		--cargo-profile "$(CARGO_PROFILE)" --tfhe-package "$(TFHE_SPEC)"
 
 .PHONY: test_shortint_multi_bit_ci # Run the tests for shortint ci running only multibit tests
 test_shortint_multi_bit_ci: install_rs_build_toolchain install_cargo_nextest
 	BIG_TESTS_INSTANCE="$(BIG_TESTS_INSTANCE)" \
 	FAST_TESTS="$(FAST_TESTS)" \
 		./scripts/shortint-tests.sh --rust-toolchain $(CARGO_RS_BUILD_TOOLCHAIN) \
-		--cargo-profile "$(CARGO_PROFILE)" --multi-bit
+		--cargo-profile "$(CARGO_PROFILE)" --multi-bit --tfhe-package "$(TFHE_SPEC)"
 
 .PHONY: test_shortint # Run all the tests for shortint
 test_shortint: install_rs_build_toolchain
@@ -424,7 +432,8 @@ test_integer_ci: install_rs_check_toolchain install_cargo_nextest
 	BIG_TESTS_INSTANCE="$(BIG_TESTS_INSTANCE)" \
 	FAST_TESTS="$(FAST_TESTS)" \
 		./scripts/integer-tests.sh --rust-toolchain $(CARGO_RS_CHECK_TOOLCHAIN) \
-		--cargo-profile "$(CARGO_PROFILE)" --avx512-support "$(AVX512_SUPPORT)"
+		--cargo-profile "$(CARGO_PROFILE)" --avx512-support "$(AVX512_SUPPORT)" \
+		--tfhe-package "$(TFHE_SPEC)"
 
 .PHONY: test_unsigned_integer_ci # Run the tests for unsigned integer ci
 test_unsigned_integer_ci: install_rs_check_toolchain install_cargo_nextest
@@ -432,7 +441,7 @@ test_unsigned_integer_ci: install_rs_check_toolchain install_cargo_nextest
 	FAST_TESTS="$(FAST_TESTS)" \
 		./scripts/integer-tests.sh --rust-toolchain $(CARGO_RS_CHECK_TOOLCHAIN) \
 		--cargo-profile "$(CARGO_PROFILE)" --avx512-support "$(AVX512_SUPPORT)" \
-		--unsigned-only
+		--unsigned-only --tfhe-package "$(TFHE_SPEC)"
 
 .PHONY: test_signed_integer_ci # Run the tests for signed integer ci
 test_signed_integer_ci: install_rs_check_toolchain install_cargo_nextest
@@ -440,14 +449,15 @@ test_signed_integer_ci: install_rs_check_toolchain install_cargo_nextest
 	FAST_TESTS="$(FAST_TESTS)" \
 		./scripts/integer-tests.sh --rust-toolchain $(CARGO_RS_CHECK_TOOLCHAIN) \
 		--cargo-profile "$(CARGO_PROFILE)" --avx512-support "$(AVX512_SUPPORT)" \
-		--signed-only
+		--signed-only --tfhe-package "$(TFHE_SPEC)"
 
 .PHONY: test_integer_multi_bit_ci # Run the tests for integer ci running only multibit tests
 test_integer_multi_bit_ci: install_rs_check_toolchain install_cargo_nextest
 	BIG_TESTS_INSTANCE="$(BIG_TESTS_INSTANCE)" \
 	FAST_TESTS="$(FAST_TESTS)" \
 		./scripts/integer-tests.sh --rust-toolchain $(CARGO_RS_CHECK_TOOLCHAIN) \
-		--cargo-profile "$(CARGO_PROFILE)" --multi-bit --avx512-support "$(AVX512_SUPPORT)"
+		--cargo-profile "$(CARGO_PROFILE)" --multi-bit --avx512-support "$(AVX512_SUPPORT)" \
+		--tfhe-package "$(TFHE_SPEC)"
 
 .PHONY: test_unsigned_integer_multi_bit_ci # Run the tests for nsigned integer ci running only multibit tests
 test_unsigned_integer_multi_bit_ci: install_rs_check_toolchain install_cargo_nextest
@@ -455,7 +465,7 @@ test_unsigned_integer_multi_bit_ci: install_rs_check_toolchain install_cargo_nex
 	FAST_TESTS="$(FAST_TESTS)" \
 		./scripts/integer-tests.sh --rust-toolchain $(CARGO_RS_CHECK_TOOLCHAIN) \
 		--cargo-profile "$(CARGO_PROFILE)" --multi-bit --avx512-support "$(AVX512_SUPPORT)" \
-		--unsigned-only
+		--unsigned-only --tfhe-package "$(TFHE_SPEC)"
 
 .PHONY: test_signed_integer_multi_bit_ci # Run the tests for nsigned integer ci running only multibit tests
 test_signed_integer_multi_bit_ci: install_rs_check_toolchain install_cargo_nextest
@@ -463,7 +473,7 @@ test_signed_integer_multi_bit_ci: install_rs_check_toolchain install_cargo_nexte
 	FAST_TESTS="$(FAST_TESTS)" \
 		./scripts/integer-tests.sh --rust-toolchain $(CARGO_RS_CHECK_TOOLCHAIN) \
 		--cargo-profile "$(CARGO_PROFILE)" --multi-bit --avx512-support "$(AVX512_SUPPORT)" \
-		--signed-only
+		--signed-only --tfhe-package "$(TFHE_SPEC)"
 
 .PHONY: test_safe_deserialization # Run the tests for safe deserialization
 test_safe_deserialization: install_rs_build_toolchain install_cargo_nextest
diff --git a/scripts/integer-tests.sh b/scripts/integer-tests.sh
index 7ca315066..f9371a397 100755
--- a/scripts/integer-tests.sh
+++ b/scripts/integer-tests.sh
@@ -12,6 +12,7 @@ function usage() {
     echo "--signed-only             Run only signed integer tests, by default both signed and unsigned tests are run"
     echo "--cargo-profile           The cargo profile used to build tests"
     echo "--avx512-support          Set to ON to enable avx512"
+    echo "--tfhe-package            The package spec like tfhe@0.4.2, default=tfhe"
     echo
 }
 
@@ -23,6 +24,7 @@ signed=""
 not_signed=""
 cargo_profile="release"
 avx512_feature=""
+tfhe_package="tfhe"
 
 while [ -n "$1" ]
 do
@@ -64,6 +66,11 @@ do
             fi
             ;;
 
+        "--tfhe-package" )
+            shift
+            tfhe_package="$1"
+            ;;
+
         *)
             echo "Unknown param : $1"
             exit 1
@@ -153,7 +160,7 @@ fi
 cargo "${RUST_TOOLCHAIN}" nextest run \
     --tests \
     --cargo-profile "${cargo_profile}" \
-    --package tfhe \
+    --package "${tfhe_package}" \
     --profile ci \
     --features="${ARCH_FEATURE}",integer,internal-keycache,"${avx512_feature}" \
     --test-threads "${test_threads}" \
@@ -162,7 +169,7 @@ cargo "${RUST_TOOLCHAIN}" nextest run \
 if [[ "${multi_bit}" == "" ]]; then
     cargo "${RUST_TOOLCHAIN}" test \
         --profile "${cargo_profile}" \
-        --package tfhe \
+        --package "${tfhe_package}" \
         --features="${ARCH_FEATURE}",integer,internal-keycache,"${avx512_feature}" \
         --doc \
         -- --test-threads="${doctest_threads}" integer::
diff --git a/scripts/shortint-tests.sh b/scripts/shortint-tests.sh
index 9f356df31..f3fce9891 100755
--- a/scripts/shortint-tests.sh
+++ b/scripts/shortint-tests.sh
@@ -9,12 +9,14 @@ function usage() {
     echo "--rust-toolchain          The toolchain to run the tests with default: stable"
     echo "--multi-bit               Run multi-bit tests only: default off"
     echo "--cargo-profile           The cargo profile used to build tests"
+    echo "--tfhe-package            The package spec like tfhe@0.4.2, default=tfhe"
     echo
 }
 
 RUST_TOOLCHAIN="+stable"
 multi_bit=""
 cargo_profile="release"
+tfhe_package="tfhe"
 
 while [ -n "$1" ]
 do
@@ -38,6 +40,11 @@ do
             cargo_profile="$1"
             ;;
 
+        "--tfhe-package" )
+            shift
+            tfhe_package="$1"
+            ;;
+
         *)
             echo "Unknown param : $1"
             exit 1
@@ -111,7 +118,7 @@ and not test(~smart_add_and_mul)""" # This test is too slow
     cargo "${RUST_TOOLCHAIN}" nextest run \
         --tests \
         --cargo-profile "${cargo_profile}" \
-        --package tfhe \
+        --package "${tfhe_package}" \
         --profile ci \
         --features="${ARCH_FEATURE}",shortint,internal-keycache \
         --test-threads "${n_threads_small}" \
@@ -128,7 +135,7 @@ and not test(~smart_add_and_mul)"""
     cargo "${RUST_TOOLCHAIN}" nextest run \
         --tests \
         --cargo-profile "${cargo_profile}" \
-        --package tfhe \
+        --package "${tfhe_package}" \
         --profile ci \
         --features="${ARCH_FEATURE}",shortint,internal-keycache \
         --test-threads "${n_threads_big}" \
@@ -137,7 +144,7 @@ and not test(~smart_add_and_mul)"""
         if [[ "${multi_bit}" == "" ]]; then
             cargo "${RUST_TOOLCHAIN}" test \
                 --profile "${cargo_profile}" \
-                --package tfhe \
+                --package "${tfhe_package}" \
                 --features="${ARCH_FEATURE}",shortint,internal-keycache \
                 --doc \
                 -- shortint::
@@ -177,7 +184,7 @@ and not test(~smart_add_and_mul)""" # This test is too slow
     cargo "${RUST_TOOLCHAIN}" nextest run \
         --tests \
         --cargo-profile "${cargo_profile}" \
-        --package tfhe \
+        --package "${tfhe_package}" \
         --profile ci \
         --features="${ARCH_FEATURE}",shortint,internal-keycache \
         --test-threads "$(${nproc_bin})" \
@@ -186,7 +193,7 @@ and not test(~smart_add_and_mul)""" # This test is too slow
     if [[ "${multi_bit}" == "" ]]; then
         cargo "${RUST_TOOLCHAIN}" test \
             --profile "${cargo_profile}" \
-            --package tfhe \
+            --package "${tfhe_package}" \
             --features="${ARCH_FEATURE}",shortint,internal-keycache \
             --doc \
             -- --test-threads="$(${nproc_bin})" shortint::