diff --git a/modules/database/src/std/link/lnkCalc.c b/modules/database/src/std/link/lnkCalc.c
index ed5796f8a..5f2b4888e 100644
--- a/modules/database/src/std/link/lnkCalc.c
+++ b/modules/database/src/std/link/lnkCalc.c
@@ -177,7 +177,7 @@ static jlif_result lnkCalc_string(jlink *pjlink, const char *val, size_t len)
     if (clink->pstate == ps_time) {
         char tinp;
 
-        if (len != 1 || (tinp = toupper((int) val[0])) < 'A' || tinp > 'L') {
+        if (len != 1 || (tinp = toupper((int) val[0])) < 'A' || tinp >= 'A' + CALCPERFORM_NARGS) {
             errlogPrintf("lnkCalc: Bad 'time' parameter \"%.*s\"\n", (int) len, val);
             return jlif_stop;
         }