diff --git a/unittest/CMakeLists.txt b/unittest/CMakeLists.txt
index f5d990d3ed..4e27f4be45 100644
--- a/unittest/CMakeLists.txt
+++ b/unittest/CMakeLists.txt
@@ -2,7 +2,7 @@ include(GTest)
 
 # check if we can run the compiled executable and whether it prints
 # the LAMMPS version header in the output for an empty input
-file(TOUCH ${CMAKE_CURRENT_BINARY_DIR}/in.empty)
+file(WRITE ${CMAKE_CURRENT_BINARY_DIR}/in.empty "")
 add_test(NAME RunLammps
          COMMAND $<TARGET_FILE:lmp> -log none -echo none -in in.empty
          WORKING_DIRECTORY ${CMAKE_CURRENT_BINARY_DIR})