diff --git a/definitions/mars/grib1.edmm.fc.def b/definitions/mars/grib1.edmm.fc.def
index 1f9d6138d..25ad10000 100644
--- a/definitions/mars/grib1.edmm.fc.def
+++ b/definitions/mars/grib1.edmm.fc.def
@@ -9,7 +9,7 @@ alias mars.date             = monthlyVerificationDate;
 # There was some forecast data produced incorrectly for stream=edmm with class=em
 # An exception is required for backward compatibility for the wrongly encoded data
 # See GRIB-422, GRIB-497
-if (class is "em" || class is "e2")
+if (class is "em" || class is "e2" || class is "ea")
 {
    alias mars.step = endStep;
 }
diff --git a/definitions/mars/grib1.ewmm.fc.def b/definitions/mars/grib1.ewmm.fc.def
index 6fe54bb8b..ea65e22ff 100644
--- a/definitions/mars/grib1.ewmm.fc.def
+++ b/definitions/mars/grib1.ewmm.fc.def
@@ -3,8 +3,8 @@ meta verificationDate         g1verificationdate(dataDate, dataTime, endStep) :
 meta monthlyVerificationDate  g1monthlydate(verificationDate) : dump,no_copy;
 alias mars.date             = monthlyVerificationDate;
 
-# See GRIB-422, GRIB-497
-if (class is "em" || class is "e2")
+# See GRIB-422, GRIB-497, GRIB-766
+if (class is "em" || class is "e2" || class is "ea")
 {
    alias mars.step = endStep;
 }
@@ -13,6 +13,5 @@ else
    alias mars.step = startStep;
 }
 
-
 alias mars.number=perturbationNumber;
 
diff --git a/definitions/mars/grib1.mnth.fc.def b/definitions/mars/grib1.mnth.fc.def
index c482340c9..4e2f666d8 100644
--- a/definitions/mars/grib1.mnth.fc.def
+++ b/definitions/mars/grib1.mnth.fc.def
@@ -4,9 +4,9 @@ meta monthlyVerificationDate  g1monthlydate(verificationDate) : dump,no_copy;
 alias mars.date             = monthlyVerificationDate;
 
 #
-# See GRIB-497
+# See GRIB-497, GRIB-766
 #
-if (class is "em" || class is "e2")
+if (class is "em" || class is "e2" || class is "ea")
 {
    alias mars.step = endStep;
 }
diff --git a/definitions/mars/grib1.wamo.fc.def b/definitions/mars/grib1.wamo.fc.def
index c482340c9..4e2f666d8 100644
--- a/definitions/mars/grib1.wamo.fc.def
+++ b/definitions/mars/grib1.wamo.fc.def
@@ -4,9 +4,9 @@ meta monthlyVerificationDate  g1monthlydate(verificationDate) : dump,no_copy;
 alias mars.date             = monthlyVerificationDate;
 
 #
-# See GRIB-497
+# See GRIB-497, GRIB-766
 #
-if (class is "em" || class is "e2")
+if (class is "em" || class is "e2" || class is "ea")
 {
    alias mars.step = endStep;
 }