diff --git a/src/co/select.c b/src/co/select.c
index 580db77..578360b 100644
--- a/src/co/select.c
+++ b/src/co/select.c
@@ -162,10 +162,11 @@ sac_history_file_set(char *name) {
     /* Null name signifies default */
     home = getenv("HOME");
     if(home) {
-      len = strlen(home) + strlen(SAC_HISTORY_FILE) + 1;
+      /* "+ 2": characters '/' and '\0' */
+      len = strlen(home) + strlen(SAC_HISTORY_FILE) + 2;
       sachistory = (char *)malloc(sizeof(char) * len);
       sprintf(sachistory,"%s/%s", home, SAC_HISTORY_FILE);
-      sachistory[len] = '\0';
+      sachistory[len - 1] = '\0';
     } else {
       sachistory = NULL;
     }