diff --git a/generator/golang.ml b/generator/golang.ml
index 4d409be83..8af124c48 100644
--- a/generator/golang.ml
+++ b/generator/golang.ml
@@ -270,20 +270,21 @@ func return_hashtable (argv **C.char) map[string]string {
         pr "type Optargs%s struct {\n" go_name;
         List.iter (
           fun optarg ->
-            let n = name_of_optargt optarg in
-            pr "    /* %s field is ignored unless %s_is_set == true */\n" n n;
-            pr "    %s_is_set bool\n" n;
+            let cn = String.capitalize (name_of_optargt optarg) in
+            pr "    /* %s field is ignored unless %s_is_set == true */\n"
+              cn cn;
+            pr "    %s_is_set bool\n" cn;
             match optarg with
-            | OBool n ->
-              pr "    %s bool\n" n
-            | OInt n ->
-              pr "    %s int\n" n
-            | OInt64 n ->
-              pr "    %s int64\n" n
-            | OString n ->
-              pr "    %s string\n" n
-            | OStringList n ->
-              pr "    %s []string\n" n
+            | OBool _ ->
+              pr "    %s bool\n" cn
+            | OInt _ ->
+              pr "    %s int\n" cn
+            | OInt64 _ ->
+              pr "    %s int64\n" cn
+            | OString _ ->
+              pr "    %s string\n" cn
+            | OStringList _ ->
+              pr "    %s []string\n" cn
         ) optargs;
         pr "}\n";
       );
@@ -395,21 +396,23 @@ func return_hashtable (argv **C.char) map[string]string {
         List.iter (
           fun optarg ->
             let n = name_of_optargt optarg in
-            pr "        if optargs.%s_is_set {\n" n;
+            let cn = String.capitalize n in
+            pr "        if optargs.%s_is_set {\n" cn;
             pr "            c_optargs.bitmask |= C.%s_%s_BITMASK\n"
               f.c_optarg_prefix (String.uppercase n);
             (match optarg with
-            | OBool n ->
-              pr "            if optargs.%s { c_optargs.%s = 1 } else { c_optargs.%s = 0}\n" n n n
-            | OInt n ->
-              pr "            c_optargs.%s = C.int (optargs.%s)\n" n n
-            | OInt64 n ->
-              pr "            c_optargs.%s = C.int64_t (optargs.%s)\n" n n
-            | OString n ->
-              pr "            c_optargs.%s = C.CString (optargs.%s)\n" n n;
+            | OBool _ ->
+              pr "            if optargs.%s { c_optargs.%s = 1 } else { c_optargs.%s = 0}\n" cn n n
+            | OInt _ ->
+              pr "            c_optargs.%s = C.int (optargs.%s)\n" n cn
+            | OInt64 _ ->
+              pr "            c_optargs.%s = C.int64_t (optargs.%s)\n" n cn
+            | OString _ ->
+              pr "            c_optargs.%s = C.CString (optargs.%s)\n" n cn;
               pr "            defer C.free (unsafe.Pointer (c_optargs.%s))\n" n
-            | OStringList n ->
-              pr "            c_optargs.%s = arg_string_list (optargs.%s)\n" n n;
+            | OStringList _ ->
+              pr "            c_optargs.%s = arg_string_list (optargs.%s)\n"
+                n cn;
               pr "            defer free_string_list (c_optargs.%s)\n" n
             );
             pr "        }\n"
diff --git a/golang/src/libguestfs.org/guestfs/guestfs_070_optargs_test.go b/golang/src/libguestfs.org/guestfs/guestfs_070_optargs_test.go
index 2dd5ad97c..ab05e8686 100644
--- a/golang/src/libguestfs.org/guestfs/guestfs_070_optargs_test.go
+++ b/golang/src/libguestfs.org/guestfs/guestfs_070_optargs_test.go
@@ -30,28 +30,28 @@ func Test070Optargs (t *testing.T) {
 		t.Errorf ("%s", err)
 	}
 	err = g.Add_drive ("/dev/null", &OptargsAdd_drive{
-		readonly_is_set: true,
-		readonly: true,
+		Readonly_is_set: true,
+		Readonly: true,
 	})
 	if err != nil {
 		t.Errorf ("%s", err)
 	}
 	err = g.Add_drive ("/dev/null", &OptargsAdd_drive{
-		readonly_is_set: true,
-		readonly: true,
-		format_is_set: true,
-		format: "raw",
+		Readonly_is_set: true,
+		Readonly: true,
+		Format_is_set: true,
+		Format: "raw",
 	})
 	if err != nil {
 		t.Errorf ("%s", err)
 	}
 	err = g.Add_drive ("/dev/null", &OptargsAdd_drive{
-		readonly_is_set: true,
-		readonly: true,
-		format_is_set: true,
-		format: "raw",
-		iface_is_set: true,
-		iface: "virtio",
+		Readonly_is_set: true,
+		Readonly: true,
+		Format_is_set: true,
+		Format: "raw",
+		Iface_is_set: true,
+		Iface: "virtio",
 	})
 	if err != nil {
 		t.Errorf ("%s", err)