diff --git a/internal/server/arg.go b/internal/server/arg.go
index 97627c5..784a37f 100644
--- a/internal/server/arg.go
+++ b/internal/server/arg.go
@@ -7,10 +7,12 @@ import (
 	"github.com/hashicorp/go-argmapper"
 )
 
-func callResourceFactory(f *argmapper.Func, provider Provider, typeName string, converter *argmapper.Func) argmapper.Result {
-	opts := []argmapper.Arg{
-		argmapper.Named("typeName", typeName),
+// TypeName represents the resource / data source type name as passed by Terraform
+type TypeName string
 
+func callResourceFactory(f *argmapper.Func, provider Provider, typeName TypeName, converter *argmapper.Func) argmapper.Result {
+	opts := []argmapper.Arg{
+		argmapper.Typed(typeName),
 		argmapper.Typed(provider),
 
 		argmapper.ConverterFunc(converter),
diff --git a/internal/server/server.go b/internal/server/server.go
index 48ab810..74611bb 100644
--- a/internal/server/server.go
+++ b/internal/server/server.go
@@ -28,8 +28,8 @@ func MustNew(providerFactoryFunc interface{}) *Server {
 
 func New(providerFactoryFunc interface{}) (*Server, error) {
 	s := &Server{
-		dsf: map[string]*argmapper.Func{},
-		rf:  map[string]*argmapper.Func{},
+		dsf: map[TypeName]*argmapper.Func{},
+		rf:  map[TypeName]*argmapper.Func{},
 	}
 
 	f, err := argmapper.NewFunc(func(p Provider) {
@@ -54,8 +54,8 @@ func New(providerFactoryFunc interface{}) (*Server, error) {
 type Server struct {
 	p Provider
 
-	dsf map[string]*argmapper.Func
-	rf  map[string]*argmapper.Func
+	dsf map[TypeName]*argmapper.Func
+	rf  map[TypeName]*argmapper.Func
 }
 
 func assertValidFactory(fn *argmapper.Func, target reflect.Type) error {
@@ -72,14 +72,14 @@ func assertValidFactory(fn *argmapper.Func, target reflect.Type) error {
 	return nil
 }
 
-func (s *Server) MustRegisterDataSource(typeName string, factory interface{}) {
+func (s *Server) MustRegisterDataSource(typeName TypeName, factory interface{}) {
 	err := s.RegisterDataSource(typeName, factory)
 	if err != nil {
 		panic(err)
 	}
 }
 
-func (s *Server) RegisterDataSource(typeName string, factory interface{}) error {
+func (s *Server) RegisterDataSource(typeName TypeName, factory interface{}) error {
 	f, err := argmapper.NewFunc(
 		factory,
 	)
@@ -103,7 +103,7 @@ func (s *Server) RegisterDataSource(typeName string, factory interface{}) error
 	return nil
 }
 
-func (s *Server) dataSource(typeName string) (DataSource, error) {
+func (s *Server) dataSource(typeName TypeName) (DataSource, error) {
 	conv, ok := s.dsf[typeName]
 	if !ok {
 		return nil, fmt.Errorf("unable to find %q", typeName)
@@ -124,14 +124,14 @@ func (s *Server) dataSource(typeName string) (DataSource, error) {
 	return ds, nil
 }
 
-func (s *Server) MustRegisterResource(typeName string, fn interface{}) {
+func (s *Server) MustRegisterResource(typeName TypeName, fn interface{}) {
 	err := s.RegisterResource(typeName, fn)
 	if err != nil {
 		panic(err)
 	}
 }
 
-func (s *Server) RegisterResource(typeName string, fn interface{}) error {
+func (s *Server) RegisterResource(typeName TypeName, fn interface{}) error {
 	f, err := argmapper.NewFunc(fn)
 	if err != nil {
 		return err
@@ -153,7 +153,7 @@ func (s *Server) RegisterResource(typeName string, fn interface{}) error {
 	return nil
 }
 
-func (s *Server) resource(typeName string) (Resource, error) {
+func (s *Server) resource(typeName TypeName) (Resource, error) {
 	conv, ok := s.rf[typeName]
 	if !ok {
 		return nil, fmt.Errorf("unable to find %q", typeName)
@@ -185,7 +185,7 @@ func (s *Server) GetProviderSchema(ctx context.Context, req *tfprotov5.GetProvid
 		if err != nil {
 			return nil, err
 		}
-		resp.DataSourceSchemas[typeName] = ds.Schema(ctx)
+		resp.DataSourceSchemas[string(typeName)] = ds.Schema(ctx)
 	}
 
 	for typeName := range s.rf {
@@ -193,7 +193,7 @@ func (s *Server) GetProviderSchema(ctx context.Context, req *tfprotov5.GetProvid
 		if err != nil {
 			return nil, err
 		}
-		resp.ResourceSchemas[typeName] = r.Schema(ctx)
+		resp.ResourceSchemas[string(typeName)] = r.Schema(ctx)
 	}
 
 	return resp, nil
@@ -265,7 +265,7 @@ func (s *Server) StopProvider(ctx context.Context, req *tfprotov5.StopProviderRe
 // ResourceServer methods
 
 func (s *Server) ValidateResourceTypeConfig(ctx context.Context, req *tfprotov5.ValidateResourceTypeConfigRequest) (*tfprotov5.ValidateResourceTypeConfigResponse, error) {
-	r, err := s.resource(req.TypeName)
+	r, err := s.resource(TypeName(req.TypeName))
 	if err != nil {
 		return nil, err
 	}
@@ -287,7 +287,7 @@ func (s *Server) ValidateResourceTypeConfig(ctx context.Context, req *tfprotov5.
 }
 
 func (s *Server) UpgradeResourceState(ctx context.Context, req *tfprotov5.UpgradeResourceStateRequest) (*tfprotov5.UpgradeResourceStateResponse, error) {
-	r, err := s.resource(req.TypeName)
+	r, err := s.resource(TypeName(req.TypeName))
 	if err != nil {
 		return nil, err
 	}
@@ -310,7 +310,7 @@ func (s *Server) UpgradeResourceState(ctx context.Context, req *tfprotov5.Upgrad
 }
 
 func (s *Server) ReadResource(ctx context.Context, req *tfprotov5.ReadResourceRequest) (*tfprotov5.ReadResourceResponse, error) {
-	r, err := s.resource(req.TypeName)
+	r, err := s.resource(TypeName(req.TypeName))
 	if err != nil {
 		return nil, err
 	}
@@ -345,7 +345,7 @@ func (s *Server) ReadResource(ctx context.Context, req *tfprotov5.ReadResourceRe
 }
 
 func (s *Server) PlanResourceChange(ctx context.Context, req *tfprotov5.PlanResourceChangeRequest) (*tfprotov5.PlanResourceChangeResponse, error) {
-	r, err := s.resource(req.TypeName)
+	r, err := s.resource(TypeName(req.TypeName))
 	if err != nil {
 		return nil, err
 	}
@@ -424,7 +424,7 @@ func (s *Server) PlanResourceChange(ctx context.Context, req *tfprotov5.PlanReso
 }
 
 func (s *Server) ApplyResourceChange(ctx context.Context, req *tfprotov5.ApplyResourceChangeRequest) (*tfprotov5.ApplyResourceChangeResponse, error) {
-	r, err := s.resource(req.TypeName)
+	r, err := s.resource(TypeName(req.TypeName))
 	if err != nil {
 		return nil, err
 	}
@@ -522,7 +522,7 @@ func (s *Server) ImportResourceState(ctx context.Context, req *tfprotov5.ImportR
 // DataSourceServer methods
 
 func (s *Server) ValidateDataSourceConfig(ctx context.Context, req *tfprotov5.ValidateDataSourceConfigRequest) (*tfprotov5.ValidateDataSourceConfigResponse, error) {
-	ds, err := s.dataSource(req.TypeName)
+	ds, err := s.dataSource(TypeName(req.TypeName))
 	if err != nil {
 		return nil, err
 	}
@@ -545,7 +545,7 @@ func (s *Server) ValidateDataSourceConfig(ctx context.Context, req *tfprotov5.Va
 }
 
 func (s *Server) ReadDataSource(ctx context.Context, req *tfprotov5.ReadDataSourceRequest) (*tfprotov5.ReadDataSourceResponse, error) {
-	ds, err := s.dataSource(req.TypeName)
+	ds, err := s.dataSource(TypeName(req.TypeName))
 	if err != nil {
 		return nil, err
 	}