diff --git a/appconfig/appconfig.go b/appconfig/appconfig.go
index 271b17c..b4d5460 100755
--- a/appconfig/appconfig.go
+++ b/appconfig/appconfig.go
@@ -224,7 +224,7 @@ func (c *AppConfig) GetConfigDesc() []string {
 	filterBuilder.WriteString("Filter: ")
 	if len(c.Filter) > 0 {
 		for _, f := range c.Filter {
-			filterBuilder.WriteString(fmt.Sprintf("\n  %s", f))
+			fmt.Fprintf(&filterBuilder, "\n  %s", f)
 		}
 	} else {
 		filterBuilder.WriteString("None")
diff --git a/installer/github_release_installer.go b/installer/github_release_installer.go
index e1968f7..69dd729 100755
--- a/installer/github_release_installer.go
+++ b/installer/github_release_installer.go
@@ -109,9 +109,9 @@ func (i *GitHubReleaseInstaller) Validate() []ValidationError {
 			errors = append(errors, ValidationError{FieldName: "destination", Message: validationIsRequired(), InstallerName: *info.Name})
 		}
 	}
-	if opts.DownloadFilename == nil || len(*opts.DownloadFilename.Resolve()) == 0 {
+	if opts.DownloadFilename == nil {
 		errors = append(errors, ValidationError{FieldName: "download_filename", Message: validationIsRequired(), InstallerName: *info.Name})
-	} else if (*opts.DownloadFilename).Resolve() == nil || len(*(*opts.DownloadFilename).Resolve()) == 0 {
+	} else if info.Platforms.GetShouldRunOnOS(platform.GetPlatform()) && (opts.DownloadFilename.Resolve() == nil || len(*opts.DownloadFilename.Resolve()) == 0) {
 		errors = append(errors, ValidationError{FieldName: fmt.Sprintf("download_filename.%s", platform.GetPlatform()), Message: validationIsRequired(), InstallerName: *info.Name})
 	}
 	if opts.Strategy != nil {
@@ -205,7 +205,7 @@ func (i *GitHubReleaseInstaller) Install() error {
 
 	filename := i.GetFilename()
 	if filename == "" {
-		return fmt.Errorf("no download filename provided")
+		return fmt.Errorf("no download filename matched for the current platform (%s/%s)", runtime.GOOS, runtime.GOARCH)
 	}
 	var machineAliases map[string]string
 	if i.Config.MachineAliases != nil {
@@ -778,7 +778,10 @@ func (i *GitHubReleaseInstaller) GetLatestTag() (string, error) {
 func (i *GitHubReleaseInstaller) GetFilename() string {
 	opts := i.GetOpts()
 	if opts.DownloadFilename != nil {
-		return *opts.DownloadFilename.Resolve()
+		resolved := opts.DownloadFilename.Resolve()
+		if resolved != nil {
+			return *resolved
+		}
 	}
 	return ""
 }
diff --git a/installer/github_release_installer_test.go b/installer/github_release_installer_test.go
index 05ac138..fafab14 100755
--- a/installer/github_release_installer_test.go
+++ b/installer/github_release_installer_test.go
@@ -4,6 +4,7 @@ import (
 	"archive/zip"
 	"bytes"
 	"compress/gzip"
+	"fmt"
 	"os"
 	"path/filepath"
 	"runtime"
@@ -75,7 +76,40 @@ func TestGitHubReleaseValidation(t *testing.T) {
 			},
 		},
 	}
-	assertValidationError(t, newTestGitHubReleaseInstaller(emptyPlatformFilename).Validate(), "download_filename")
+	assertValidationError(t, newTestGitHubReleaseInstaller(emptyPlatformFilename).Validate(), fmt.Sprintf("download_filename.%s", platform.GetPlatform()))
+
+	// 🟢 download_filename only defined for another platform, but installer is restricted to that platform — should pass
+	otherPlatform := platform.PlatformLinux
+	if platform.GetPlatform() == platform.PlatformLinux {
+		otherPlatform = platform.PlatformMacos
+	}
+	otherPlatformOnly := &appconfig.InstallerData{
+		Name:      lo.ToPtr("ghr-other-platform-only"),
+		Type:      appconfig.InstallerTypeGitHubRelease,
+		Platforms: &platform.Platforms{Only: &[]platform.Platform{otherPlatform}},
+		Opts: &map[string]any{
+			"repository":  "owner/repo",
+			"destination": "/some/path",
+			"download_filename": map[string]*string{
+				string(otherPlatform): lo.ToPtr("file.tar.gz"),
+			},
+		},
+	}
+	assertNoValidationErrors(t, newTestGitHubReleaseInstaller(otherPlatformOnly).Validate())
+
+	// 🔴 download_filename missing for current platform when installer runs on current platform
+	missingCurrentPlatform := &appconfig.InstallerData{
+		Name: lo.ToPtr("ghr-missing-current-platform"),
+		Type: appconfig.InstallerTypeGitHubRelease,
+		Opts: &map[string]any{
+			"repository":  "owner/repo",
+			"destination": "/some/path",
+			"download_filename": map[string]*string{
+				string(otherPlatform): lo.ToPtr("file.tar.gz"),
+			},
+		},
+	}
+	assertValidationError(t, newTestGitHubReleaseInstaller(missingCurrentPlatform).Validate(), fmt.Sprintf("download_filename.%s", platform.GetPlatform()))
 
 	// 🔴 Invalid strategy
 	invalidStrategy := &appconfig.InstallerData{