diff --git a/Sources/StringStyle+Part.swift b/Sources/StringStyle+Part.swift
index 776ecce4..a2845d51 100644
--- a/Sources/StringStyle+Part.swift
+++ b/Sources/StringStyle+Part.swift
@@ -165,7 +165,7 @@ extension StringStyle {
     mutating func update(part stylePart: Part) {
         switch stylePart {
         case let .extraAttributes(attributes):
-            self.extraAttributes = attributes
+            self.add(extraAttributes: attributes)
         case let .font(font):
             self.font = font
         case let .link(link):
diff --git a/Tests/AttributedStringStyleTests.swift b/Tests/AttributedStringStyleTests.swift
index 8e43bba8..aa7fd901 100644
--- a/Tests/AttributedStringStyleTests.swift
+++ b/Tests/AttributedStringStyleTests.swift
@@ -829,6 +829,15 @@ class StringStyleTests: XCTestCase {
         BONAssert(attributes: childAttributes, key: .foregroundColor, value: BONColor.black)
     }
 
+    func testOverridingExtraAttributesPart() {
+        let style = StringStyle()
+            .byAdding(.extraAttributes([.backgroundColor: BONColor.white]))
+            .byAdding(.extraAttributes([.foregroundColor: BONColor.black]))
+
+        BONAssert(attributes: style.attributes, key: .backgroundColor, value: BONColor.white)
+        BONAssert(attributes: style.attributes, key: .foregroundColor, value: BONColor.black)
+    }
+
 }
 
 private extension StringStyleTests {