diff --git a/DDTest/CMakeLists.txt b/DDTest/CMakeLists.txt
index ac51cb3196ed07d7b4d6cd613a98bf072b37552d..4f065e2586635a94d9851683085668f03ce8ce8e 100644
--- a/DDTest/CMakeLists.txt
+++ b/DDTest/CMakeLists.txt
@@ -64,7 +64,7 @@ if (DD4HEP_USE_GEANT4)
 
   ADD_TEST( t_test_ddsim "${CMAKE_INSTALL_PREFIX}/bin/run_test.sh"
     ddsim --compactFile=${CMAKE_INSTALL_PREFIX}/DDDetectors/compact/SiD.xml --runType=batch -G -N=2 --outputFile=testSid.root
-    --gun.position "0.0 0.0 0.0" --gun.direction "1.0 0.0 1.0" --gun.energy 100*GeV --part.userParticleHandler=)
+    --gun.position \"0.0 0.0 1.0*cm\" --gun.direction \"1.0 0.0 1.0\" --gun.energy 100*GeV --part.userParticleHandler=)
   SET_TESTS_PROPERTIES( t_test_ddsim PROPERTIES FAIL_REGULAR_EXPRESSION  "Exception;EXCEPTION;ERROR;Error" )
 
 endif()
diff --git a/cmake/run_test.sh b/cmake/run_test.sh
index aed7ac0a27e67e49f45002918fd4d29784427e09..eab04a6c239c9265583353ef42ebfbcf1bb91d99 100755
--- a/cmake/run_test.sh
+++ b/cmake/run_test.sh
@@ -24,4 +24,4 @@ done
 echo " #### LD_LIBRARY_PATH = :  ${LD_LIBRARY_PATH}"
 
 echo "---running test :  '" ${command} ${theargs} "'"
-${command} ${theargs}
+eval ${command} ${theargs}