diff --git a/example/generated.go b/example/generated.go
index 1533d13..1e45927 100644
--- a/example/generated.go
+++ b/example/generated.go
@@ -31,6 +31,7 @@ func getViewer(
 	var retval getViewerResponse
 	err := client.MakeRequest(
 		ctx,
+		"getViewer",
 		`
 query getViewer {
 	viewer {
@@ -57,6 +58,7 @@ func getUser(
 	var retval getUserResponse
 	err := client.MakeRequest(
 		ctx,
+		"getUser",
 		`
 query getUser ($Login: String!) {
 	user(login: $Login) {
diff --git a/generate/operation.go.tmpl b/generate/operation.go.tmpl
index cfa5148..b332b4c 100644
--- a/generate/operation.go.tmpl
+++ b/generate/operation.go.tmpl
@@ -40,6 +40,7 @@ func {{.Name}}(
 	var retval {{.ResponseName}}
     err := {{if $.Config.ClientGetter}}{{$.Config.ClientGetter}}{{else}}client{{end}}.MakeRequest(
         {{if $.Config.ContextType}}ctx{{else}}nil{{end}},
+        "{{.Name}}",
         `{{.Body}}`,
         &retval,
         {{if .Args}}variables{{else}}nil{{end}},
diff --git a/generate/testdata/InputObject.graphql.go b/generate/testdata/InputObject.graphql.go
index 284fc90..3b37e44 100644
--- a/generate/testdata/InputObject.graphql.go
+++ b/generate/testdata/InputObject.graphql.go
@@ -40,6 +40,7 @@ func InputObjectQuery(
 	var retval InputObjectQueryResponse
 	err := client.MakeRequest(
 		nil,
+		"InputObjectQuery",
 		`
 query InputObjectQuery ($query: UserQueryInput) {
 	user(query: $query) {
diff --git a/generate/testdata/InterfaceNoFragments.graphql.go b/generate/testdata/InterfaceNoFragments.graphql.go
index 422f348..7250611 100644
--- a/generate/testdata/InterfaceNoFragments.graphql.go
+++ b/generate/testdata/InterfaceNoFragments.graphql.go
@@ -99,6 +99,7 @@ func InterfaceNoFragmentsQuery(
 	var retval InterfaceNoFragmentsQueryResponse
 	err := client.MakeRequest(
 		nil,
+		"InterfaceNoFragmentsQuery",
 		`
 query InterfaceNoFragmentsQuery {
 	root {
diff --git a/generate/testdata/ListInput.graphql.go b/generate/testdata/ListInput.graphql.go
index ff01793..94d7164 100644
--- a/generate/testdata/ListInput.graphql.go
+++ b/generate/testdata/ListInput.graphql.go
@@ -25,6 +25,7 @@ func ListInputQuery(
 	var retval ListInputQueryResponse
 	err := client.MakeRequest(
 		nil,
+		"ListInputQuery",
 		`
 query ListInputQuery ($names: [String]) {
 	user(query: {names:$names}) {
diff --git a/generate/testdata/QueryWithAlias.graphql.go b/generate/testdata/QueryWithAlias.graphql.go
index 5fca827..57bef7a 100644
--- a/generate/testdata/QueryWithAlias.graphql.go
+++ b/generate/testdata/QueryWithAlias.graphql.go
@@ -20,6 +20,7 @@ func QueryWithAlias(
 	var retval QueryWithAliasResponse
 	err := client.MakeRequest(
 		nil,
+		"QueryWithAlias",
 		`
 query QueryWithAlias {
 	User: user {
diff --git a/generate/testdata/QueryWithDoubleAlias.graphql.go b/generate/testdata/QueryWithDoubleAlias.graphql.go
index 1c1b9a7..448c7b2 100644
--- a/generate/testdata/QueryWithDoubleAlias.graphql.go
+++ b/generate/testdata/QueryWithDoubleAlias.graphql.go
@@ -21,6 +21,7 @@ func QueryWithDoubleAlias(
 	var retval QueryWithDoubleAliasResponse
 	err := client.MakeRequest(
 		nil,
+		"QueryWithDoubleAlias",
 		`
 query QueryWithDoubleAlias {
 	user {
diff --git a/generate/testdata/QueryWithEnums.graphql.go b/generate/testdata/QueryWithEnums.graphql.go
index 7ef0f68..c943844 100644
--- a/generate/testdata/QueryWithEnums.graphql.go
+++ b/generate/testdata/QueryWithEnums.graphql.go
@@ -27,6 +27,7 @@ func QueryWithEnums(
 	var retval QueryWithEnumsResponse
 	err := client.MakeRequest(
 		nil,
+		"QueryWithEnums",
 		`
 query QueryWithEnums {
 	user {
diff --git a/generate/testdata/QueryWithSlices.graphql.go b/generate/testdata/QueryWithSlices.graphql.go
index b9091bc..4dc684c 100644
--- a/generate/testdata/QueryWithSlices.graphql.go
+++ b/generate/testdata/QueryWithSlices.graphql.go
@@ -23,6 +23,7 @@ func QueryWithSlices(
 	var retval QueryWithSlicesResponse
 	err := client.MakeRequest(
 		nil,
+		"QueryWithSlices",
 		`
 query QueryWithSlices {
 	user {
diff --git a/generate/testdata/QueryWithStructs.graphql.go b/generate/testdata/QueryWithStructs.graphql.go
index 9a9559a..bcdef77 100644
--- a/generate/testdata/QueryWithStructs.graphql.go
+++ b/generate/testdata/QueryWithStructs.graphql.go
@@ -25,6 +25,7 @@ func QueryWithStructs(
 	var retval QueryWithStructsResponse
 	err := client.MakeRequest(
 		nil,
+		"QueryWithStructs",
 		`
 query QueryWithStructs {
 	user {
diff --git a/generate/testdata/SimpleInput.graphql.go b/generate/testdata/SimpleInput.graphql.go
index 2127493..441e498 100644
--- a/generate/testdata/SimpleInput.graphql.go
+++ b/generate/testdata/SimpleInput.graphql.go
@@ -25,6 +25,7 @@ func SimpleInputQuery(
 	var retval SimpleInputQueryResponse
 	err := client.MakeRequest(
 		nil,
+		"SimpleInputQuery",
 		`
 query SimpleInputQuery ($name: String!) {
 	user(query: {name:$name}) {
diff --git a/generate/testdata/SimpleQuery.graphql.go b/generate/testdata/SimpleQuery.graphql.go
index ab1e804..49382e9 100644
--- a/generate/testdata/SimpleQuery.graphql.go
+++ b/generate/testdata/SimpleQuery.graphql.go
@@ -20,6 +20,7 @@ func SimpleQuery(
 	var retval SimpleQueryResponse
 	err := client.MakeRequest(
 		nil,
+		"SimpleQuery",
 		`
 query SimpleQuery {
 	user {
diff --git a/generate/testdata/TypeName.graphql.go b/generate/testdata/TypeName.graphql.go
index d2bf790..4a07f0d 100644
--- a/generate/testdata/TypeName.graphql.go
+++ b/generate/testdata/TypeName.graphql.go
@@ -21,6 +21,7 @@ func TypeNameQuery(
 	var retval TypeNameQueryResponse
 	err := client.MakeRequest(
 		nil,
+		"TypeNameQuery",
 		`
 query TypeNameQuery {
 	user {
diff --git a/generate/testdata/UnionNoFragments.graphql.go b/generate/testdata/UnionNoFragments.graphql.go
index fe64fb3..e47fd38 100644
--- a/generate/testdata/UnionNoFragments.graphql.go
+++ b/generate/testdata/UnionNoFragments.graphql.go
@@ -77,6 +77,7 @@ func UnionNoFragmentsQuery(
 	var retval UnionNoFragmentsQueryResponse
 	err := client.MakeRequest(
 		nil,
+		"UnionNoFragmentsQuery",
 		`
 query UnionNoFragmentsQuery {
 	randomLeaf {
diff --git a/generate/testdata/UsesEnumTwice.graphql.go b/generate/testdata/UsesEnumTwice.graphql.go
index 84e099b..97ee3c7 100644
--- a/generate/testdata/UsesEnumTwice.graphql.go
+++ b/generate/testdata/UsesEnumTwice.graphql.go
@@ -39,6 +39,7 @@ func UsesEnumTwiceQuery(
 	var retval UsesEnumTwiceQueryResponse
 	err := client.MakeRequest(
 		nil,
+		"UsesEnumTwiceQuery",
 		`
 query UsesEnumTwiceQuery {
 	Me: user {
diff --git a/generate/testdata/unexported.graphql.go b/generate/testdata/unexported.graphql.go
index a9fb34e..a88dd63 100644
--- a/generate/testdata/unexported.graphql.go
+++ b/generate/testdata/unexported.graphql.go
@@ -40,6 +40,7 @@ func unexported(
 	var retval unexportedResponse
 	err := client.MakeRequest(
 		nil,
+		"unexported",
 		`
 query unexported ($query: UserQueryInput) {
 	user(query: $query) {
diff --git a/graphql/client.go b/graphql/client.go
index a8cdd3a..707a320 100644
--- a/graphql/client.go
+++ b/graphql/client.go
@@ -40,6 +40,7 @@ type Client interface {
 	// (Errors are returned.) But again, MakeRequest may customize this.
 	MakeRequest(
 		ctx context.Context,
+		opName string,
 		query string,
 		retval interface{},
 		variables map[string]interface{},
@@ -68,10 +69,12 @@ func NewClient(endpoint string, httpClient *http.Client) Client {
 	return &client{endpoint, http.MethodPost, httpClient}
 }
 
-// TODO: set OperationName?
 type payload struct {
 	Query     string                 `json:"query"`
 	Variables map[string]interface{} `json:"variables"`
+	// OpName is only required if there are multiple queries in the document,
+	// but we set it unconditionally, because that's easier.
+	OpName string `json:"operationName"`
 }
 
 type response struct {
@@ -79,10 +82,11 @@ type response struct {
 	Errors gqlerror.List `json:"errors"`
 }
 
-func (c *client) MakeRequest(ctx context.Context, query string, retval interface{}, variables map[string]interface{}) error {
+func (c *client) MakeRequest(ctx context.Context, opName string, query string, retval interface{}, variables map[string]interface{}) error {
 	body, err := json.Marshal(payload{
 		Query:     query,
 		Variables: variables,
+		OpName:    opName,
 	})
 	if err != nil {
 		return err