diff --git a/cmd/pgconfigctl/cmd/tune.go b/cmd/pgconfigctl/cmd/tune.go
index b3a2548..2cfb6d7 100644
--- a/cmd/pgconfigctl/cmd/tune.go
+++ b/cmd/pgconfigctl/cmd/tune.go
@@ -64,26 +64,35 @@ var tuneCmd = &cobra.Command{
 			logFormat = "jsonlog"
 		}
 
-		out, err := rules.Compute(
-			*input.NewInput(
-				osName,
-				arch,
-				totalRAM,
-				totalCPU,
-				profileName,
-				diskType,
-				maxConnections,
-				pgVersion))
+		in := *input.NewInput(
+			osName,
+			arch,
+			totalRAM,
+			totalCPU,
+			profileName,
+			diskType,
+			maxConnections,
+			pgVersion)
+		output, err := tune(in, outputFormat, includePgbadger, logFormat)
 
 		if err != nil {
 			panic(err)
 		}
 
-		data := out.ToSlice(pgVersion, includePgbadger, logFormat)
-		fmt.Println(format.ExportConf(outputFormat, data, pgVersion, nil))
+		fmt.Println(output)
 	},
 }
 
+func tune(in input.Input, outputFormat format.ExportFormat, includePgbadger bool, logFormat string) (string, error) {
+	result, err := rules.Tune(rules.NewTuningRequest(in))
+	if err != nil {
+		return "", err
+	}
+
+	data := result.CompatibilityProjection().ToSlice(in.PostgresVersion, includePgbadger, logFormat)
+	return format.ExportConf(outputFormat, data, in.PostgresVersion, nil), nil
+}
+
 func init() {
 
 	memory, err := memory.Get()
diff --git a/cmd/pgconfigctl/cmd/tune_test.go b/cmd/pgconfigctl/cmd/tune_test.go
new file mode 100644
index 0000000..ee12cb6
--- /dev/null
+++ b/cmd/pgconfigctl/cmd/tune_test.go
@@ -0,0 +1,85 @@
+package cmd
+
+import (
+	"runtime"
+	"strings"
+	"testing"
+
+	"github.com/pgconfig/api/pkg/defaults"
+	"github.com/pgconfig/api/pkg/format"
+	"github.com/pgconfig/api/pkg/input"
+	"github.com/pgconfig/api/pkg/input/bytes"
+	"github.com/pgconfig/api/pkg/input/profile"
+	"github.com/pgconfig/api/pkg/rules"
+)
+
+func TestTunePreservesLegacyOutput(t *testing.T) {
+	tests := []struct {
+		name            string
+		input           input.Input
+		includePgbadger bool
+		logFormat       string
+	}{
+		{
+			name: "explicit inputs",
+			input: *input.NewInput(
+				"linux", "amd64", 16*bytes.GB, 8, profile.OLTP, "SSD", 200, 16,
+			),
+			includePgbadger: true,
+			logFormat:       "jsonlog",
+		},
+		{
+			name: "flag defaults",
+			input: *input.NewInput(
+				"linux", "amd64", 8*bytes.GB, 4, profile.Web, "SSD", 100, defaults.PGVersionF,
+			),
+			logFormat: "csvlog",
+		},
+		{
+			name: "autodetected resources",
+			input: *input.NewInput(
+				runtime.GOOS, runtime.GOARCH, totalRAM, runtime.NumCPU(), profile.Web, "SSD", 100, defaults.PGVersionF,
+			),
+			logFormat: "jsonlog",
+		},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			legacy, err := rules.Compute(tt.input)
+			if err != nil {
+				t.Fatalf("compute legacy recommendations: %v", err)
+			}
+
+			for _, outputFormat := range format.AllExportFormats {
+				t.Run(string(outputFormat), func(t *testing.T) {
+					want := format.ExportConf(
+						outputFormat,
+						legacy.ToSlice(tt.input.PostgresVersion, tt.includePgbadger, tt.logFormat),
+						tt.input.PostgresVersion,
+						nil,
+					)
+					got, err := tune(tt.input, outputFormat, tt.includePgbadger, tt.logFormat)
+					if err != nil {
+						t.Fatalf("tune: %v", err)
+					}
+					if got != want {
+						t.Errorf("output changed\nwant:\n%s\ngot:\n%s", want, got)
+					}
+				})
+			}
+		})
+	}
+}
+
+func TestTuneKeepsLegacyListenAddresses(t *testing.T) {
+	in := *input.NewInput("linux", "amd64", 8*bytes.GB, 4, profile.Web, "SSD", 100, 16)
+
+	output, err := tune(in, format.Config, false, "csvlog")
+	if err != nil {
+		t.Fatalf("tune: %v", err)
+	}
+	if !strings.Contains(output, "listen_addresses") {
+		t.Fatal("legacy CLI output omitted listen_addresses")
+	}
+}