diff --git a/color.go b/color.go
index 86c9ca1..0303704 100644
--- a/color.go
+++ b/color.go
@@ -65,6 +65,16 @@ func (c NRGBA) RGBA() (r, g, b, a uint32) {
 	return
 }
 
+func clamp(x, low, high float64) float64 {
+	if x < low {
+		return low
+	}
+	if x > high {
+		return high
+	}
+	return x
+}
+
 // NRGBAModel converts colors to NRGBA format.
 var NRGBAModel = color.ModelFunc(nrgbaModel)
 
diff --git a/util.go b/util.go
deleted file mode 100644
index 24e6199..0000000
--- a/util.go
+++ /dev/null
@@ -1,11 +0,0 @@
-package pixel
-
-func clamp(x, low, high float64) float64 {
-	if x < low {
-		return low
-	}
-	if x > high {
-		return high
-	}
-	return x
-}