diff --git a/Library/Homebrew/api/formula_struct.rb b/Library/Homebrew/api/formula_struct.rb
index 44b7be5f89110..44b86ec046a8f 100644
--- a/Library/Homebrew/api/formula_struct.rb
+++ b/Library/Homebrew/api/formula_struct.rb
@@ -47,8 +47,8 @@ def self.from_hash(formula_hash)
           T.any(
             # Formula name: "foo"
             String,
-            # Formula name and dependency type: { "foo" => :build }
-            T::Hash[String, Symbol],
+            # Formula name and dependency types: { "foo" => :build } or { "foo" => [:test, :no_linkage] }
+            T::Hash[String, T.any(Symbol, T::Array[Symbol])],
           ),
           # Requirements
           T.any(
diff --git a/Library/Homebrew/test/api/formula_struct_spec.rb b/Library/Homebrew/test/api/formula_struct_spec.rb
index 679367d8e0999..cb93a716dc18f 100644
--- a/Library/Homebrew/test/api/formula_struct_spec.rb
+++ b/Library/Homebrew/test/api/formula_struct_spec.rb
@@ -284,6 +284,21 @@ def build_formula_struct(checksums)
       expect(restored).to eq(original)
     end
 
+    it "preserves tagged dependencies after serialize then deserialize" do
+      original = described_class.new(
+        desc:                 "tagged dependencies",
+        homepage:             "https://example.com",
+        license:              "MIT",
+        ruby_source_checksum: "abc123",
+        stable_version:       "1.0.0",
+        stable_dependencies:  ["dep1", { "dep2" => :no_linkage }, { "dep3" => [:test, :no_linkage] }],
+      )
+
+      restored = described_class.deserialize(original.serialize)
+
+      expect(restored.stable_dependencies).to eq(original.stable_dependencies)
+    end
+
     it "serializes post-install steps", :needs_macos do
       original = described_class.new(
         desc:                 "install steps test",