diff --git a/asterix-runtime/src/main/resources/adm.grammar b/asterix-runtime/src/main/resources/adm.grammar
index 56c7212..4d4158f 100644
--- a/asterix-runtime/src/main/resources/adm.grammar
+++ b/asterix-runtime/src/main/resources/adm.grammar
@@ -26,9 +26,9 @@
 RECTANGLE_CONS = string(rectangle)
 CIRCLE_CONS    = string(circle)
 TIME_CONS      = string(time)
-INTERVAL_TIME_CONS      = string(interval_time)
-INTERVAL_DATE_CONS      = string(interval_date)
-INTERVAL_DATETIME_CONS  = string(interval_datetime)
+INTERVAL_TIME_CONS      = string(interval-time)
+INTERVAL_DATE_CONS      = string(interval-date)
+INTERVAL_DATETIME_CONS  = string(interval-datetime)
 
 NULL_LITERAL   = string(null)
 TRUE_LITERAL   = string(true)