diff --git a/config/bondethernet.py b/config/bondethernet.py
index 000708c..3238712 100644
--- a/config/bondethernet.py
+++ b/config/bondethernet.py
@@ -63,10 +63,19 @@ def validate_bondethernets(yaml):
 
     for ifname, iface in yaml['bondethernets'].items():
         logger.debug("bondethernet %s: %s" % (ifname, iface))
+        bond_ifname, bond_iface = interface.get_by_name(yaml, ifname)
+        bond_mtu = 1500
+        if not bond_iface:
+            msgs.append("bondethernet %s does not exist in interfaces" % (ifname))
+            result = False
+        else:
+            bond_mtu = interface.get_mtu(yaml, bond_ifname)
+
         for member in iface['interfaces']:
             if (None, None) == interface.get_by_name(yaml, member):
                 msgs.append("bondethernet %s member %s does not exist" % (ifname, member))
                 result = False
+                continue
 
             if interface.has_sub(yaml, member):
                 msgs.append("bondethernet %s member %s has sub-interface(s)" % (ifname, member))
@@ -77,4 +86,8 @@ def validate_bondethernets(yaml):
             if interface.has_address(yaml, member):
                 msgs.append("bondethernet %s member %s has an address" % (ifname, member))
                 result = False
+            member_mtu = interface.get_mtu(yaml, member)
+            if  member_mtu != bond_mtu:
+                msgs.append("bondethernet %s member %s MTU %d does not match BondEthernet MTU %d" % (ifname, member, member_mtu, bond_mtu))
+                result = False
     return result, msgs
diff --git a/unittest/yaml/correct-bridgedomain.yaml b/unittest/yaml/correct-bridgedomain.yaml
index 4a4d5f5..617d54e 100644
--- a/unittest/yaml/correct-bridgedomain.yaml
+++ b/unittest/yaml/correct-bridgedomain.yaml
@@ -25,9 +25,9 @@ interfaces:
         mtu: 2000
 
   GigabitEthernet3/0/0:
-    mtu: 9000
+    mtu: 3000
   GigabitEthernet3/0/1:
-    mtu: 9000
+    mtu: 3000
 
   GigabitEthernet4/0/0:
     mtu: 9000
diff --git a/unittest/yaml/correct-l2xc.yaml b/unittest/yaml/correct-l2xc.yaml
index 6bc9a55..814dbfb 100644
--- a/unittest/yaml/correct-l2xc.yaml
+++ b/unittest/yaml/correct-l2xc.yaml
@@ -31,6 +31,7 @@ interfaces:
     mtu: 3000
 
   BondEthernet0:
+    mtu: 3000
     description: "BE0 with two xconnected sub-ints"
     sub-interfaces:
       100:
diff --git a/unittest/yaml/error-bondethernet5.yaml b/unittest/yaml/error-bondethernet5.yaml
new file mode 100644
index 0000000..79d9c38
--- /dev/null
+++ b/unittest/yaml/error-bondethernet5.yaml
@@ -0,0 +1,22 @@
+test:
+  description: "Members of a BondEthernet must have the same MTU as their bond"
+  errors:
+    expected:
+     - "bondethernet .* member .* MTU 2500 does not match BondEthernet MTU 3000"
+     - "bondethernet .* member .* MTU 2000 does not match BondEthernet MTU 3000"
+    count: 2
+---
+bondethernets:
+  BondEthernet0:
+    interfaces: [ GigabitEthernet2/0/0, GigabitEthernet2/0/1 ]
+
+interfaces:
+  GigabitEthernet2/0/0:
+    mtu: 2500
+    description: "LAG with default MTU, needs to be 3000"
+  GigabitEthernet2/0/1:
+    mtu: 2000
+    description: "LAG with default MTU, needs to be 3000"
+
+  BondEthernet0:
+    mtu: 3000
diff --git a/unittest/yaml/error-bondethernet6.yaml b/unittest/yaml/error-bondethernet6.yaml
new file mode 100644
index 0000000..8c81e64
--- /dev/null
+++ b/unittest/yaml/error-bondethernet6.yaml
@@ -0,0 +1,20 @@
+test:
+  description: "A BondEthernet entry must also be an interface"
+  errors:
+    expected:
+     - "bondethernet .* does not exist in interfaces"
+    count: 1
+---
+bondethernets:
+  BondEthernet0:
+    interfaces: [ GigabitEthernet2/0/0, GigabitEthernet2/0/1 ]
+
+interfaces:
+  GigabitEthernet2/0/0:
+    description: "LAG #2"
+  GigabitEthernet2/0/1:
+    description: "LAG #2"
+
+  # BondEthenet0:
+  #   description: "This entry should exist"
+  #   mtu: 1500