diff --git a/configure.ac b/configure.ac
index 35a7dfa47..24b8850d1 100644
--- a/configure.ac
+++ b/configure.ac
@@ -16,7 +16,7 @@
 # problem to the user.
 AC_PREREQ([2.59])
 
-m4_define([ngspice_major_version], [35])
+m4_define([ngspice_major_version], [35+])
 m4_define([ngspice_minor_version], [0])
 m4_define([ngspice_version],
       [ngspice_major_version])
diff --git a/visualc/src/include/ngspice/config.h b/visualc/src/include/ngspice/config.h
index 437e36df1..ae83a095d 100644
--- a/visualc/src/include/ngspice/config.h
+++ b/visualc/src/include/ngspice/config.h
@@ -449,7 +449,7 @@
 #define PACKAGE "ngspice"
 
 /* Version number of package */
-#define VERSION "35" //" Built on " __DATE__ " at " __TIME__
+#define VERSION "35+" //" Built on " __DATE__ " at " __TIME__
 
 /* Define to the address where bug reports for this package should be sent. */
 #define PACKAGE_BUGREPORT "http://ngspice.sourceforge.net/bugrep.html"