diff --git a/src/lib66/ss_environ.c b/src/lib66/ss_environ.c
index 97f2eaf59739ff3d2b141110167793e11a05b5e0..ddfdd1af38c420cf5628259950150bdade527c11 100644
--- a/src/lib66/ss_environ.c
+++ b/src/lib66/ss_environ.c
@@ -264,6 +264,8 @@ int env_append_version(stralloc *saversion, char const *svconf, char const *vers
     if (!env_check_version(&sa,version))
         return 0 ;
 
+    saversion->len = 0 ;
+
     if (!auto_stra(saversion,svconf,"/",sa.s))
         log_warnusys_return(LOG_EXIT_ZERO,"stralloc") ;