diff --git a/pkg/cmd/repo/setdefault/setdefault.go b/pkg/cmd/repo/setdefault/setdefault.go
index 63596d259..71c993b9d 100644
--- a/pkg/cmd/repo/setdefault/setdefault.go
+++ b/pkg/cmd/repo/setdefault/setdefault.go
@@ -89,21 +89,23 @@ func NewCmdSetDefault(f *cmdutil.Factory, runF func(*SetDefaultOptions) error) *
 			}
 
 			if len(args) > 0 {
-				// First, try to find argument as a git remote name
-				if !strings.Contains(args[0], "/") && opts.Remotes != nil {
-					if remotes, err := opts.Remotes(); err == nil {
-						if remote, err := remotes.FindByName(args[0]); err == nil {
-							opts.Repo = remote.Repo
-						}
+				var err error
+				opts.Repo, err = ghrepo.FromFullName(args[0])
+				if err != nil {
+					if opts.Remotes == nil {
+						return fmt.Errorf("given arg is not a valid repo or git remote: %w", err)
 					}
-				}
-				// If not found as remote name, try parsing as OWNER/REPO
-				if opts.Repo == nil {
-					var err error
-					opts.Repo, err = ghrepo.FromFullName(args[0])
-					if err != nil {
-						return err
+
+					remotes, remoteErr := opts.Remotes()
+					if remoteErr != nil {
+						return remoteErr
 					}
+
+					remote, findErr := remotes.FindByName(args[0])
+					if findErr != nil {
+						return fmt.Errorf("given arg is not a valid repo or git remote: %w", err)
+					}
+					opts.Repo = remote.Repo
 				}
 			}
 
diff --git a/pkg/cmd/repo/setdefault/setdefault_test.go b/pkg/cmd/repo/setdefault/setdefault_test.go
index e910676ee..eb8d6282c 100644
--- a/pkg/cmd/repo/setdefault/setdefault_test.go
+++ b/pkg/cmd/repo/setdefault/setdefault_test.go
@@ -50,7 +50,7 @@ func TestNewCmdSetDefault(t *testing.T) {
 			},
 			input:   "some_invalid_format",
 			wantErr: true,
-			errMsg:  `expected the "[HOST/]OWNER/REPO" format, got "some_invalid_format"`,
+			errMsg:  `given arg is not a valid repo or git remote: expected the "[HOST/]OWNER/REPO" format, got "some_invalid_format"`,
 		},
 		{
 			name: "view flag",
@@ -93,6 +93,22 @@ func TestNewCmdSetDefault(t *testing.T) {
 			input:  "origin",
 			output: SetDefaultOptions{Repo: ghrepo.New("OWNER", "REPO")},
 		},
+		{
+			name: "repo argument despite remote name matching owner/repo",
+			gitStubs: func(cs *run.CommandStubber) {
+				cs.Register(`git rev-parse --git-dir`, 0, ".git")
+			},
+			remotes: func() (context.Remotes, error) {
+				return context.Remotes{
+					{
+						Remote: &git.Remote{Name: "OWNER/REPO"},
+						Repo:   ghrepo.New("OTHER", "REPO"),
+					},
+				}, nil
+			},
+			input:  "OWNER/REPO",
+			output: SetDefaultOptions{Repo: ghrepo.New("OWNER", "REPO")},
+		},
 	}
 
 	for _, tt := range tests {