diff --git a/rascaline-c-api/CMakeLists.txt b/rascaline-c-api/CMakeLists.txt
index 0e887dfd8..041d6c467 100644
--- a/rascaline-c-api/CMakeLists.txt
+++ b/rascaline-c-api/CMakeLists.txt
@@ -60,7 +60,7 @@ set(RUST_BUILD_TARGET "" CACHE STRING "Cross-compilation target for rust code. L
 set(EXTRA_RUST_FLAGS "" CACHE STRING "Flags used to build rust code")
 mark_as_advanced(RUST_BUILD_TARGET EXTRA_RUST_FLAGS)
 
-option(RASCALINE_ENABLE_CHEMFILES "Disable the usage of chemfiles for reading structures from files" ON)
+option(RASCALINE_ENABLE_CHEMFILES "Enable the usage of chemfiles for reading structures from files" OFF)
 option(RASCALINE_FETCH_EQUISTORE "Download and build the equistore C API before building rascaline" OFF)
 
 set(CMAKE_MACOSX_RPATH ON)
diff --git a/rascaline-c-api/tests/CMakeLists.txt b/rascaline-c-api/tests/CMakeLists.txt
index 782901d82..02be53b03 100644
--- a/rascaline-c-api/tests/CMakeLists.txt
+++ b/rascaline-c-api/tests/CMakeLists.txt
@@ -49,6 +49,7 @@ else()
     string(TOLOWER ${CMAKE_BUILD_TYPE} CMAKE_BUILD_TYPE)
 endif()
 
+set(RASCALINE_ENABLE_CHEMFILES ON)
 add_subdirectory(${CMAKE_CURRENT_SOURCE_DIR}/.. ${CMAKE_CURRENT_BINARY_DIR}/rascaline)
 
 
diff --git a/rascaline/src/systems/chemfiles.rs b/rascaline/src/systems/chemfiles.rs
index a3f7dbd1f..cc19e9153 100644
--- a/rascaline/src/systems/chemfiles.rs
+++ b/rascaline/src/systems/chemfiles.rs
@@ -73,7 +73,8 @@ pub fn read_from_file(path: impl AsRef<Path>) -> Result<Vec<SimpleSystem>, Error
 #[cfg(not(feature = "chemfiles"))]
 pub fn read_from_file(_: impl AsRef<Path>) -> Result<Vec<SimpleSystem>, Error> {
     Err(Error::Chemfiles(
-        "read_from_file is only available with the chemfiles feature enabled".into()
+        "read_from_file is only available with the chemfiles feature enabled \
+        (RASCALINE_ENABLE_CHEMFILES=ON in CMake)".into()
     ))
 }