diff --git a/c_gen/build_of_g.py b/c_gen/build_of_g.py
index f117bfd..85be353 100755
--- a/c_gen/build_of_g.py
+++ b/c_gen/build_of_g.py
@@ -153,6 +153,11 @@
             # but is variable length
             bytes = -1
             len_update = 8
+        elif base_type == "of_oxm_header_t":
+            # This is a special case: it has non-zero min length
+            # but is variable length
+            bytes = -1
+            len_update = 4
         elif base_type in of_g.of_base_types:
             bytes = of_g.of_base_types[base_type]["bytes"]
         else:
@@ -330,7 +335,7 @@
                 else:
                     # HACK the C backend does not yet support of_oxm_t
                     if m.oftype == 'of_oxm_t':
-                        m_type = 'of_octets_t'
+                        m_type = 'of_oxm_header_t'
                     else:
                         enum = find(lambda e: e.name == m.oftype, protocol.enums)
                         if enum and "wire_type" in enum.params:
diff --git a/c_gen/c_code_gen.py b/c_gen/c_code_gen.py
index b43675a..91bd07f 100644
--- a/c_gen/c_code_gen.py
+++ b/c_gen/c_code_gen.py
@@ -1671,6 +1671,17 @@
     match_octets.data = OF_OBJECT_BUFFER_INDEX(obj, offset);
     OF_TRY(of_match_deserialize(ver, %(m_name)s, &match_octets));
 """ % dict(m_name=m_name))
+    elif m_type == "of_oxm_header_t":
+        out.write("""
+    /* Initialize child */
+    %(m_type)s_init(%(m_name)s, obj->version, 0, 1);
+    /* Attach to parent */
+    %(m_name)s->parent = (of_object_t *)obj;
+    %(m_name)s->wbuf = obj->wbuf;
+    %(m_name)s->obj_offset = abs_offset;
+    %(m_name)s->length = cur_len;
+    of_object_wire_init(%(m_name)s, OF_OXM, 0);
+""" % dict(m_type=m_type[:-2], m_name=m_name))
     else:
         out.write("""
     /* Initialize child */
diff --git a/c_gen/c_test_gen.py b/c_gen/c_test_gen.py
index 2ca743a..a0cdca1 100644
--- a/c_gen/c_test_gen.py
+++ b/c_gen/c_test_gen.py
@@ -99,6 +99,7 @@
         of_octets_t="octets",
         of_meter_features_t="features",
         of_match_t="match",
+        of_oxm_header_t="oxm",
         # BSN extensions
         of_bsn_vport_q_in_q_t="vport",
         of_bitmap_128_t="bitmap_128",