diff --git a/cmd/compose/ps.go b/cmd/compose/ps.go
index 2528fccacfb..e79a8bcef89 100644
--- a/cmd/compose/ps.go
+++ b/cmd/compose/ps.go
@@ -81,7 +81,7 @@ func psCommand(p *ProjectOptions, dockerCli command.Cli, backendOptions *Backend
 		ValidArgsFunction: completeServiceNames(dockerCli, p),
 	}
 	flags := psCmd.Flags()
-	flags.StringVar(&opts.Format, "format", "table", cliflags.FormatHelp)
+	flags.StringVar(&opts.Format, "format", "", cliflags.FormatHelp)
 	flags.StringVar(&opts.Filter, "filter", "", "Filter services by a property (supported filters: status)")
 	flags.StringArrayVar(&opts.Status, "status", []string{}, "Filter services by status. Values: [paused | restarting | removing | running | dead | created | exited]")
 	flags.BoolVarP(&opts.Quiet, "quiet", "q", false, "Only display IDs")
@@ -152,9 +152,14 @@ func runPs(ctx context.Context, dockerCli command.Cli, backendOptions *BackendOp
 		return nil
 	}
 
-	if opts.Format == "" {
+	if len(opts.Format) == 0 {
 		opts.Format = dockerCli.ConfigFile().PsFormat
 	}
+	if len(opts.Format) == 0 {
+		opts.Format = "table"
+	} else if opts.Quiet {
+		_, _ = dockerCli.Err().Write([]byte("WARNING: Ignoring custom format, because both --format and --quiet are set.\n"))
+	}
 
 	containerCtx := cliformatter.Context{
 		Output: dockerCli.Out(),
diff --git a/cmd/compose/ps_format_test.go b/cmd/compose/ps_format_test.go
new file mode 100644
index 00000000000..b36c0788953
--- /dev/null
+++ b/cmd/compose/ps_format_test.go
@@ -0,0 +1,47 @@
+/*
+   Copyright 2020 Docker Compose CLI authors
+
+   Licensed under the Apache License, Version 2.0 (the "License");
+   you may not use this file except in compliance with the License.
+   You may obtain a copy of the License at
+
+       http://www.apache.org/licenses/LICENSE-2.0
+
+   Unless required by applicable law or agreed to in writing, software
+   distributed under the License is distributed on an "AS IS" BASIS,
+   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+   See the License for the specific language governing permissions and
+   limitations under the License.
+*/
+
+package compose
+
+import (
+	"testing"
+
+	"github.com/docker/cli/cli/config/configfile"
+	"github.com/docker/cli/cli/streams"
+	"go.uber.org/mock/gomock"
+	"gotest.tools/v3/assert"
+
+	"github.com/docker/compose/v5/pkg/mocks"
+)
+
+func TestPsCommandDefaultFormat(t *testing.T) {
+	// Test that the format flag has empty string as default
+	projectOpts := &ProjectOptions{}
+	mockCtrl := gomock.NewController(t)
+	defer mockCtrl.Finish()
+
+	cli := mocks.NewMockCli(mockCtrl)
+	cli.EXPECT().ConfigFile().Return(configfile.New("test")).AnyTimes()
+	cli.EXPECT().Out().Return(&streams.Out{}).AnyTimes()
+	cli.EXPECT().Err().Return(&streams.Out{}).AnyTimes()
+
+	backendOptions := &BackendOptions{}
+	cmd := psCommand(projectOpts, cli, backendOptions)
+
+	// Check default value of format flag
+	formatFlag := cmd.Flags().Lookup("format")
+	assert.Equal(t, formatFlag.DefValue, "")
+}