diff --git a/cmake/generate_version_file.cmake b/cmake/generate_version_file.cmake
index c4a579d1..07b4b43b 100644
--- a/cmake/generate_version_file.cmake
+++ b/cmake/generate_version_file.cmake
@@ -19,17 +19,20 @@ if(status AND NOT status EQUAL 0)
     # for source package files (generated for ubuntu builds on launchpad) read the version from version.txt
     if(EXISTS ${CMAKE_CURRENT_LIST_DIR}/../version.txt)
       file(READ ${CMAKE_CURRENT_LIST_DIR}/../version.txt git_version_string )
+      string(STRIP "${git_version_string}" git_version_string)
     else()
       get_filename_component(git_version_string ${CMAKE_CURRENT_LIST_DIR}/.. NAME)
       string(REGEX REPLACE "^netgen(.*)" "\\1" git_version_string "${git_version_string}")
     endif()
-  else()
-    MESSAGE(WARNING "Could not determine git-version from source code - assuming 6.2.0.0")
-    set(git_version_string "v6.2.0.0")
   endif()
 endif()
 string(STRIP ${git_version_string} git_version_string)
 
+if (NOT git_version_string)
+  message(WARNING "Could not determine git-version from source code - assuming 6.2.0.0")
+  set(git_version_string "v6.2.0.0")
+endif ()
+
 string(REGEX REPLACE "^v([0-9]+)\\..*" "\\1" NETGEN_VERSION_MAJOR "${git_version_string}")
 string(REGEX REPLACE "^v[0-9]+\\.([0-9]+).*" "\\1" NETGEN_VERSION_MINOR "${git_version_string}")
 string(REGEX REPLACE "^v[0-9]+\\.[0-9]+\\.([0-9]+).*" "\\1" NETGEN_VERSION_PATCH "${git_version_string}")