diff --git a/generate/generate.go b/generate/generate.go
index f8d8472..f1d8b1c 100644
--- a/generate/generate.go
+++ b/generate/generate.go
@@ -51,15 +51,19 @@ type argument struct {
 	GraphQLName string
 }
 
-func fromASTArg(arg *ast.VariableDefinition, schema *ast.Schema) argument {
+func fromASTArg(arg *ast.VariableDefinition, schema *ast.Schema) (argument, error) {
 	graphQLName := arg.Variable
 	firstRest := strings.SplitN(graphQLName, "", 2)
 	goName := strings.ToLower(firstRest[0]) + firstRest[1]
+	goType, err := typeForInputType(arg.Type, schema)
+	if err != nil {
+		return argument{}, err
+	}
 	return argument{
 		GraphQLName: graphQLName,
 		GoName:      goName,
-		GoType:      typeForInputType(arg.Type, schema),
-	}
+		GoType:      goType,
+	}, nil
 }
 
 func reverse(slice []string) {
@@ -100,7 +104,11 @@ func fromASTOperation(op *ast.OperationDefinition, schema *ast.Schema) (operatio
 
 	args := make([]argument, len(op.VariableDefinitions))
 	for i, arg := range op.VariableDefinitions {
-		args[i] = fromASTArg(arg, schema)
+		var err error
+		args[i], err = fromASTArg(arg, schema)
+		if err != nil {
+			return operation{}, err
+		}
 	}
 
 	typ, err := typeForOperation(op, schema)
diff --git a/generate/types.go b/generate/types.go
index 3614f64..ea45dba 100644
--- a/generate/types.go
+++ b/generate/types.go
@@ -13,14 +13,14 @@ func typeForOperation(operation *ast.OperationDefinition, schema *ast.Schema) (s
 	return builder.String(), err
 }
 
-func typeForInputType(typ *ast.Type, schema *ast.Schema) string {
+func typeForInputType(typ *ast.Type, schema *ast.Schema) (string, error) {
 	var builder strings.Builder
 
 	// TODO: handle non-scalar types (by passing ...something... as the
 	// SelectionSet?)
-	writeType(&builder, typ, nil, schema)
+	err := writeType(&builder, typ, nil, schema)
 
-	return builder.String()
+	return builder.String(), err
 }
 
 func writeSelectionSetStruct(builder *strings.Builder, selectionSet ast.SelectionSet, schema *ast.Schema) error {
@@ -46,7 +46,10 @@ func writeSelectionSetStruct(builder *strings.Builder, selectionSet ast.Selectio
 				// but empirically it might not.
 				return fmt.Errorf("undefined selection %v", selection)
 			}
-			writeType(builder, selection.Definition.Type, selection.SelectionSet, schema)
+			err := writeType(builder, selection.Definition.Type, selection.SelectionSet, schema)
+			if err != nil {
+				return err
+			}
 
 			if jsonName != goName {
 				builder.WriteString("`json:\"")