diff --git a/definitions/mars/grib.oper.ep.def b/definitions/mars/grib.oper.ep.def
new file mode 100644
index 000000000..9d067c931
--- /dev/null
+++ b/definitions/mars/grib.oper.ep.def
@@ -0,0 +1,4 @@
+if (class is "ai")
+{
+ alias mars.step = stepRange;
+}