diff --git a/internal/xds/env/env.go b/internal/xds/env/env.go
index 035b92b18f13..1110722a630b 100644
--- a/internal/xds/env/env.go
+++ b/internal/xds/env/env.go
@@ -61,16 +61,16 @@ var (
 	// When both bootstrap FileName and FileContent are set, FileName is used.
 	BootstrapFileContent = os.Getenv(BootstrapFileContentEnv)
 	// CircuitBreakingSupport indicates whether circuit breaking support is
-	// enabled, which can be done by setting the environment variable
-	// "GRPC_XDS_EXPERIMENTAL_CIRCUIT_BREAKING" to "true".
-	CircuitBreakingSupport = strings.EqualFold(os.Getenv(circuitBreakingSupportEnv), "true")
+	// enabled, which can be disabled by setting the environment variable
+	// "GRPC_XDS_EXPERIMENTAL_CIRCUIT_BREAKING" to "false".
+	CircuitBreakingSupport = !strings.EqualFold(os.Getenv(circuitBreakingSupportEnv), "false")
 	// TimeoutSupport indicates whether support for max_stream_duration in
-	// route actions is enabled.  This can be enabled by setting the
-	// environment variable "GRPC_XDS_EXPERIMENTAL_ENABLE_TIMEOUT" to "true".
-	TimeoutSupport = strings.EqualFold(os.Getenv(timeoutSupportEnv), "true")
+	// route actions is enabled.  This can be disabled by setting the
+	// environment variable "GRPC_XDS_EXPERIMENTAL_ENABLE_TIMEOUT" to "false".
+	TimeoutSupport = !strings.EqualFold(os.Getenv(timeoutSupportEnv), "false")
 	// FaultInjectionSupport is used to control both fault injection and HTTP
 	// filter support.
-	FaultInjectionSupport = strings.EqualFold(os.Getenv(faultInjectionSupportEnv), "true")
+	FaultInjectionSupport = !strings.EqualFold(os.Getenv(faultInjectionSupportEnv), "false")
 	// C2PResolverSupport indicates whether support for C2P resolver is enabled.
 	// This can be enabled by setting the environment variable
 	// "GRPC_EXPERIMENTAL_GOOGLE_C2P_RESOLVER" to "true".
diff --git a/xds/csds/csds_test.go b/xds/csds/csds_test.go
index 856894b4e4d4..2993beea0e5d 100644
--- a/xds/csds/csds_test.go
+++ b/xds/csds/csds_test.go
@@ -25,11 +25,6 @@ import (
 	"testing"
 	"time"
 
-	v3adminpb "github.com/envoyproxy/go-control-plane/envoy/admin/v3"
-	v2corepb "github.com/envoyproxy/go-control-plane/envoy/api/v2/core"
-	v3clusterpb "github.com/envoyproxy/go-control-plane/envoy/config/cluster/v3"
-	v3endpointpb "github.com/envoyproxy/go-control-plane/envoy/config/endpoint/v3"
-	v3routepb "github.com/envoyproxy/go-control-plane/envoy/config/route/v3"
 	"github.com/golang/protobuf/jsonpb"
 	"github.com/golang/protobuf/proto"
 	"github.com/golang/protobuf/ptypes"
@@ -39,14 +34,20 @@ import (
 	"google.golang.org/grpc"
 	"google.golang.org/grpc/internal/xds"
 	"google.golang.org/grpc/xds/internal/client"
+	_ "google.golang.org/grpc/xds/internal/httpfilter/router"
 	"google.golang.org/grpc/xds/internal/testutils"
 	"google.golang.org/grpc/xds/internal/testutils/e2e"
 	"google.golang.org/protobuf/testing/protocmp"
 	"google.golang.org/protobuf/types/known/anypb"
 	"google.golang.org/protobuf/types/known/timestamppb"
 
+	v3adminpb "github.com/envoyproxy/go-control-plane/envoy/admin/v3"
+	v2corepb "github.com/envoyproxy/go-control-plane/envoy/api/v2/core"
+	v3clusterpb "github.com/envoyproxy/go-control-plane/envoy/config/cluster/v3"
 	v3corepb "github.com/envoyproxy/go-control-plane/envoy/config/core/v3"
+	v3endpointpb "github.com/envoyproxy/go-control-plane/envoy/config/endpoint/v3"
 	v3listenerpb "github.com/envoyproxy/go-control-plane/envoy/config/listener/v3"
+	v3routepb "github.com/envoyproxy/go-control-plane/envoy/config/route/v3"
 	v3statuspb "github.com/envoyproxy/go-control-plane/envoy/service/status/v3"
 )