diff --git a/src/configure.ac b/src/configure.ac
index cc8d61f..2db0449 100644
--- a/src/configure.ac
+++ b/src/configure.ac
@@ -1436,7 +1436,7 @@
     dnl -- get its version number
     AC_CACHE_CHECK(Python version,vi_cv_var_python3_version,
     [[vi_cv_var_python3_version=`
-          ${vi_cv_path_python3} -c 'import sys; print(sys.version[:3])'`
+          ${vi_cv_path_python3} -c 'import sys; print("{}.{}".format(sys.version_info.major, sys.version_info.minor))'`
     ]])
 
     dnl -- it must be at least version 3