diff --git a/pkg/downloader/manager.go b/pkg/downloader/manager.go
index a5b0af080..d0f101dab 100644
--- a/pkg/downloader/manager.go
+++ b/pkg/downloader/manager.go
@@ -659,9 +659,27 @@ func (m *Manager) UpdateRepositories() error {
 	return nil
 }
 
+// Filter out duplicate repos by URL, including those with trailing slashes.
+func dedupeRepos(repos []*repo.Entry) []*repo.Entry {
+	seen := make(map[string]*repo.Entry)
+	for _, r := range repos {
+		// Normalize URL by removing trailing slashes.
+		r.URL = strings.TrimSuffix(r.URL, "/")
+		seen[r.URL] = r
+	}
+	var unique []*repo.Entry
+	for _, r := range seen {
+		unique = append(unique, r)
+	}
+	return unique
+}
+
 func (m *Manager) parallelRepoUpdate(repos []*repo.Entry) error {
 
 	var wg sync.WaitGroup
+
+	repos = dedupeRepos(repos)
+
 	for _, c := range repos {
 		r, err := repo.NewChartRepository(c, m.Getters)
 		if err != nil {
diff --git a/pkg/downloader/manager_test.go b/pkg/downloader/manager_test.go
index f7ab1a568..13c94e116 100644
--- a/pkg/downloader/manager_test.go
+++ b/pkg/downloader/manager_test.go
@@ -26,6 +26,7 @@ import (
 	"helm.sh/helm/v3/pkg/chart/loader"
 	"helm.sh/helm/v3/pkg/chartutil"
 	"helm.sh/helm/v3/pkg/getter"
+	"helm.sh/helm/v3/pkg/repo"
 	"helm.sh/helm/v3/pkg/repo/repotest"
 )
 
@@ -572,3 +573,71 @@ func TestKey(t *testing.T) {
 		}
 	}
 }
+
+// Test dedupeRepos tests that the dedupeRepos function correctly deduplicates
+func TestDedupeRepos(t *testing.T) {
+	tests := []struct {
+		name  string
+		repos []*repo.Entry
+		want  []*repo.Entry
+	}{
+		{
+			name: "no duplicates",
+			repos: []*repo.Entry{
+				{
+					URL: "https://example.com/charts",
+				},
+				{
+					URL: "https://example.com/charts2",
+				},
+			},
+			want: []*repo.Entry{
+				{
+					URL: "https://example.com/charts",
+				},
+				{
+					URL: "https://example.com/charts2",
+				},
+			},
+		},
+		{
+			name: "duplicates",
+			repos: []*repo.Entry{
+				{
+					URL: "https://example.com/charts",
+				},
+				{
+					URL: "https://example.com/charts",
+				},
+			},
+			want: []*repo.Entry{
+				{
+					URL: "https://example.com/charts",
+				},
+			},
+		},
+		{
+			name: "duplicates with trailing slash",
+			repos: []*repo.Entry{
+				{
+					URL: "https://example.com/charts",
+				},
+				{
+					URL: "https://example.com/charts/",
+				},
+			},
+			want: []*repo.Entry{
+				{
+					URL: "https://example.com/charts",
+				},
+			},
+		},
+	}
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			if got := dedupeRepos(tt.repos); !reflect.DeepEqual(got, tt.want) {
+				t.Errorf("received:\n%v\nwant:\n%v", got, tt.want)
+			}
+		})
+	}
+}