diff --git a/library/yap2swi/yap2swi.c b/library/yap2swi/yap2swi.c
index 102a65b00..9fece0719 100755
--- a/library/yap2swi/yap2swi.c
+++ b/library/yap2swi/yap2swi.c
@@ -2461,7 +2461,12 @@ SWI_ctime(void)
     return FALSE;
   }
 #if HAVE_CTIME
-  tim = (time_t)YAP_FloatOfTerm(t1);
+  if (YAP_IsIntTerm(t1))
+    tim = (time_t)YAP_IntOfTerm(t1);
+  else if (YAP_IsFloatTerm(t1))
+    tim = (time_t)YAP_FloatOfTerm(t1);
+  else
+    return FALSE;
   return YAP_Unify(YAP_BufferToString(ctime(&tim)), YAP_ARG2);
 #else
   YAP_Error(0,0L,"convert_time requires ctime");