diff --git a/Geant4/G4config/CMakeLists.txt b/Geant4/G4config/CMakeLists.txt
index 3107b524911f9eb46bf22492b92099b1aedd63d7..873ade54948f17d6f01e46bdbbe014fb84fbf0b4 100644
--- a/Geant4/G4config/CMakeLists.txt
+++ b/Geant4/G4config/CMakeLists.txt
@@ -31,6 +31,10 @@ if(DEFINED ENV{G4_NATIVE_VERSION})
 else()
   set(Geant4_tag ${CMAKE_PROJECT_VERSION})
 endif()
+# Special mapping of version HEAD
+if(Geant4_tag STREQUAL "HEAD")
+  set(Geant4_tag master)
+endif()
 
 include(ExternalProject)