diff --git a/cmake/DPF-plugin.cmake b/cmake/DPF-plugin.cmake
index c277b339..4d1cd0a8 100644
--- a/cmake/DPF-plugin.cmake
+++ b/cmake/DPF-plugin.cmake
@@ -482,7 +482,7 @@ function(dpf__ensure_sources_non_empty VAR)
   if(NOT "" STREQUAL "${${VAR}}")
     return()
   endif()
-  set(_file "${CMAKE_CURRENT_BINARY_DIR}/_dpf_empty.cpp")
+  set(_file "${CMAKE_CURRENT_BINARY_DIR}/_dpf_empty.c")
   if(NOT EXISTS "${_file}")
     file(WRITE "${_file}" "")
   endif()