diff --git a/pkg/flag/report_flags.go b/pkg/flag/report_flags.go
index de5f9a3226e0..9747d4816751 100644
--- a/pkg/flag/report_flags.go
+++ b/pkg/flag/report_flags.go
@@ -26,7 +26,7 @@ var (
 		ConfigName: "format",
 		Shorthand:  "f",
 		Value:      report.FormatTable,
-		Usage:      "format (table, json, sarif, template, cyclonedx, spdx, spdx-json, github, cosign-vuln)",
+		Usage:      "format (" + strings.Join(report.SupportedFormats, ", ") + ")",
 	}
 	ReportFormatFlag = Flag{
 		Name:       "report",
@@ -155,6 +155,10 @@ func (f *ReportFlagGroup) ToOptions(out io.Writer) (ReportOptions, error) {
 	listAllPkgs := getBool(f.ListAllPkgs)
 	output := getString(f.Output)
 
+	if format != "" && !slices.Contains(report.SupportedFormats, format) {
+		return ReportOptions{}, xerrors.Errorf("unknown format: %v", format)
+	}
+
 	if template != "" {
 		if format == "" {
 			log.Logger.Warn("'--template' is ignored because '--format template' is not specified. Use '--template' option with '--format template' option.")
diff --git a/pkg/report/writer.go b/pkg/report/writer.go
index 2f727ada71a2..6bc0a7881bad 100644
--- a/pkg/report/writer.go
+++ b/pkg/report/writer.go
@@ -32,6 +32,10 @@ const (
 	FormatCosignVuln = "cosign-vuln"
 )
 
+var (
+	SupportedFormats = []string{FormatTable, FormatJSON, FormatTemplate, FormatSarif, FormatCycloneDX, FormatSPDX, FormatSPDXJSON, FormatGitHub, FormatCosignVuln}
+)
+
 var (
 	SupportedSBOMFormats = []string{FormatCycloneDX, FormatSPDX, FormatSPDXJSON, FormatGitHub}
 )