diff --git a/configure.ac b/configure.ac
index 4f9e05347..d73fe1b39 100644
--- a/configure.ac
+++ b/configure.ac
@@ -12,7 +12,7 @@
 # ---------------
 
 # Initialisation of configure
-AC_INIT([ngspice], [31], [http://ngspice.sourceforge.net/bugrep.html])
+AC_INIT([ngspice], [31+], [http://ngspice.sourceforge.net/bugrep.html])
 
 # Unique file in the source directory
 AC_CONFIG_SRCDIR([src/ngspice.c])
diff --git a/visualc/src/include/ngspice/config.h b/visualc/src/include/ngspice/config.h
index ad9b82f2f..506605728 100644
--- a/visualc/src/include/ngspice/config.h
+++ b/visualc/src/include/ngspice/config.h
@@ -455,13 +455,13 @@
 #define PACKAGE_NAME "ngspice"
 
 /* Define to the full name and version of this package. */
-#define PACKAGE_STRING "ngspice 31"
+#define PACKAGE_STRING "ngspice 31+"
 
 /* Define to the one symbol short name of this package. */
 #define PACKAGE_TARNAME "ngspice"
 
 /* Define to the version of this package. */
-#define PACKAGE_VERSION "31"
+#define PACKAGE_VERSION "31+"
 
 /* Define if we want predictor algorithm */
 /* #undef PREDICTOR */
@@ -516,7 +516,7 @@
 /* #undef TM_IN_SYS_TIME */
 
 /* Version number of package */
-#define VERSION "31"
+#define VERSION "31+"
 
 /* Define if we want spice2 sensitivity analysis */
 /* #undef WANT_SENSE2 */