diff --git a/.ci/test.sh b/.ci/test.sh
index 2a20ce054c9e..b0a8dbd0d766 100755
--- a/.ci/test.sh
+++ b/.ci/test.sh
@@ -153,17 +153,17 @@ if [[ $TASK == "check-docs" ]] || [[ $TASK == "check-links" ]]; then
 fi
 
 if [[ $PYTHON_VERSION == "3.7" ]]; then
-    CONDA_REQUIREMENT_FILES="--file ${BUILD_DIRECTORY}/.ci/conda-envs/ci-core-py37.txt"
+    CONDA_REQUIREMENT_FILES="${BUILD_DIRECTORY}/.ci/conda-envs/ci-core-py37.txt"
 elif [[ $PYTHON_VERSION == "3.8" ]]; then
-    CONDA_REQUIREMENT_FILES="--file ${BUILD_DIRECTORY}/.ci/conda-envs/ci-core-py38.txt"
+    CONDA_REQUIREMENT_FILES="${BUILD_DIRECTORY}/.ci/conda-envs/ci-core-py38.txt"
 else
-    CONDA_REQUIREMENT_FILES="--file ${BUILD_DIRECTORY}/.ci/conda-envs/ci-core.txt"
+    CONDA_REQUIREMENT_FILES="${BUILD_DIRECTORY}/.ci/conda-envs/ci-core.txt"
 fi
 
 mamba create \
     -y \
     -n $CONDA_ENV \
-    "${CONDA_REQUIREMENT_FILES}" \
+    --file "${CONDA_REQUIREMENT_FILES}" \
     "${CONDA_PYTHON_REQUIREMENT}" \
 || exit 1