Index: /issm/trunk-jpl/m4/issm_options.m4
===================================================================
--- /issm/trunk-jpl/m4/issm_options.m4	(revision 24674)
+++ /issm/trunk-jpl/m4/issm_options.m4	(revision 24675)
@@ -700,5 +700,5 @@
 			dnl the best way to do this: it's what "site.py" does in the
 			dnl standard library.
-			PYTHON_VERSION=$(${PYTHON_ROOT}/bin/python -c "import sys; print(sys.version[:3])")
+			PYTHON_VERSION=$(${PYTHON_ROOT}/bin/python -c "import sys; print(sys.version[[:3]])")
 			AC_MSG_RESULT([${PYTHON_VERSION}])
 		else