diff --git a/Installation/cmake/modules/CGAL_UseRS.cmake b/Installation/cmake/modules/CGAL_UseRS.cmake
index b4cdaa7dcd2..32162b90773 100644
--- a/Installation/cmake/modules/CGAL_UseRS.cmake
+++ b/Installation/cmake/modules/CGAL_UseRS.cmake
@@ -39,7 +39,7 @@ if( NOT CGAL_RS_SETUP )
 
       # extract RS3 version from the file rsversion.h (based on Fernando
       # Cacciola's code for FindBoost.cmake)
-      if(EXISTS "${RS3_INCLUDE_DIR}/rsversion.h")
+      if( EXISTS "${RS3_INCLUDE_DIR}/rsversion.h" )
         FILE(READ "${RS3_INCLUDE_DIR}/rsversion.h" _rsversion_h_CONTENTS)
         STRING(REGEX REPLACE ".*#define[ \t]+rs_major[ \t]+([0-9]+).*"
                              "\\1" RS3_MAJOR "${_rsversion_h_CONTENTS}")
@@ -47,13 +47,21 @@ if( NOT CGAL_RS_SETUP )
                              "\\1" RS3_MIDDLE "${_rsversion_h_CONTENTS}")
         STRING(REGEX REPLACE ".*#define[ \t]+rs_minor[ \t]+([0-9]+).*"
                              "\\1" RS3_MINOR "${_rsversion_h_CONTENTS}")
-        SET(RS3_LIB_VERSION "${RS3_MAJOR}.${RS3_MIDDLE}.${RS3_MINOR}")
-      else(EXISTS "${RS3_INCLUDE_DIR}/rsversion.h")
-        SET(RS3_LIB_VERSION "unknown")
-      endif(EXISTS "${RS3_INCLUDE_DIR}/rsversion.h")
+        SET( RS3_LIB_VERSION "${RS3_MAJOR}.${RS3_MIDDLE}.${RS3_MINOR}" )
+        IS_VERSION_LESS( "${RS3_MAJOR}.${RS3_MIDDLE}" "3.1" RS_OLD_INCLUDES )
+      else( EXISTS "${RS3_INCLUDE_DIR}/rsversion.h" )
+        # rsversion.h did not exist in old versions
+        SET( RS3_LIB_VERSION "unknown" )
+        SET( RS_OLD_INCLUDES TRUE )
+      endif( EXISTS "${RS3_INCLUDE_DIR}/rsversion.h" )
 
       message( STATUS "RS version is ${RS3_LIB_VERSION}" )
 
+      if( RS_OLD_INCLUDES )
+        add_definitions( "-DCGAL_RS_OLD_INCLUDES" )
+        message( STATUS "Using old RS signatures" )
+      endif( RS_OLD_INCLUDES )
+
     endif( RS3_FOUND )
 
   endif( RS_FOUND )