diff --git a/xc7/family.cmake b/xc7/family.cmake
index 6d24b405..ade5dd73 100644
--- a/xc7/family.cmake
+++ b/xc7/family.cmake
@@ -1,6 +1,6 @@
 # Adapted https://cliutils.gitlab.io/modern-cmake/chapters/projects/submodule.html
 find_package(Git QUIET)
-if(GIT_FOUND AND EXISTS ".gitmodules")
+if(GIT_FOUND AND EXISTS "${CMAKE_CURRENT_SOURCE_DIR}/.gitmodules")
 # Update submodules as needed
     option(GIT_SUBMODULE "Check submodules during build" ON)
     if(GIT_SUBMODULE)