diff --git a/rascaline-c-api/CMakeLists.txt b/rascaline-c-api/CMakeLists.txt
index 55163e4bc..0ab39ff5d 100644
--- a/rascaline-c-api/CMakeLists.txt
+++ b/rascaline-c-api/CMakeLists.txt
@@ -300,11 +300,18 @@ if (NOT "${EXTRA_RUST_FLAGS}" STREQUAL "")
     set(CARGO_RUSTC_ARGS "${CARGO_RUSTC_ARGS};${EXTRA_RUST_FLAGS}")
 endif()
 
+# Set environement variables for cargo build
+set(CARGO_ENV "")
+if (NOT "${CMAKE_OSX_DEPLOYMENT_TARGET}" STREQUAL "")
+    list(APPEND CARGO_ENV "MACOSX_DEPLOYMENT_TARGET=${CMAKE_OSX_DEPLOYMENT_TARGET}")
+endif()
+if (NOT "$ENV{RUSTC_WRAPPER}" STREQUAL "")
+    list(APPEND CARGO_ENV "RUSTC_WRAPPER=$ENV{RUSTC_WRAPPER}")
+endif()
+
 add_custom_target(cargo-build-rascaline ALL
     COMMAND
-        ${CMAKE_COMMAND} -E env
-        MACOSX_DEPLOYMENT_TARGET=${CMAKE_OSX_DEPLOYMENT_TARGET}
-        RUSTC_WRAPPER=$ENV{RUSTC_WRAPPER}
+        ${CMAKE_COMMAND} -E env ${CARGO_ENV}
         cargo rustc ${CARGO_BUILD_ARG} -- ${CARGO_RUSTC_ARGS}
     WORKING_DIRECTORY ${PROJECT_SOURCE_DIR}
     DEPENDS ${ALL_RUST_SOURCES}