diff --git a/Sources/AudioKitUI/Controls/ParameterSlider.swift b/Sources/AudioKitUI/Controls/ParameterSlider.swift
index 5f33aa8..c2217ec 100644
--- a/Sources/AudioKitUI/Controls/ParameterSlider.swift
+++ b/Sources/AudioKitUI/Controls/ParameterSlider.swift
@@ -12,7 +12,7 @@ public struct ParameterSlider: View {
     public init(text: String,
                 parameter: Binding<Float>,
                 range: ClosedRange<AUValue>,
-                units: String) {
+                units: String = "") {
         _parameter = parameter
         self.text = text
         self.range = range