diff --git a/vulkan/CMakeLists.txt b/vulkan/CMakeLists.txt
index 2680878..977faf5 100644
--- a/vulkan/CMakeLists.txt
+++ b/vulkan/CMakeLists.txt
@@ -325,8 +325,8 @@ macro(run_external_revision_generate source_dir symbol_name output)
     # NOTE: If you modify this call to use --rev_file instead of --git_dir (to read the commit ID from a file instead of
     # parsing from a Git repository), you probably also want to add the revision file to the list of DEPENDS on the
     # subsequent line (to ensure that the script is re-run when the revision file is modified).
-    COMMAND ${PYTHON_CMD} ${SCRIPTS_DIR}/external_revision_generator.py --git_dir ${source_dir} -s ${symbol_name} -o ${output}
-    DEPENDS ${SCRIPTS_DIR}/external_revision_generator.py ${source_dir}/.git/HEAD ${source_dir}/.git/index
+    COMMAND ${PYTHON_CMD} ${SCRIPTS_DIR}/external_revision_generator.py --rev_file ${source_dir}/rev_file -s ${symbol_name} -o ${output}
+    DEPENDS ${source_dir}/rev_file
     )
 endmacro()