diff --git a/Attributes.go b/Attributes.go
index 23ae418..f301d7c 100644
--- a/Attributes.go
+++ b/Attributes.go
@@ -23,6 +23,11 @@ func NewAttributes() (*Attributes, error) {
 	return &Attributes{p: pAttr}, nil
 }
 
+const (
+	COLORS_MIN = 2
+	COLORS_MAX = 256
+)
+
 func (this *Attributes) SetMaxColors(colors int) error {
 	return translateError(C.liq_set_max_colors(this.p, C.int(colors)))
 }
@@ -31,6 +36,11 @@ func (this *Attributes) GetMaxColors() int {
 	return int(C.liq_get_max_colors(this.p))
 }
 
+const (
+	QUALITY_MIN = 0
+	QUALITY_MAX = 100
+)
+
 func (this *Attributes) SetQuality(minimum, maximum int) error {
 	return translateError(C.liq_set_quality(this.p, C.int(minimum), C.int(maximum)))
 }
@@ -43,6 +53,12 @@ func (this *Attributes) GetMaxQuality() int {
 	return int(C.liq_get_max_quality(this.p))
 }
 
+const (
+	SPEED_SLOWEST = 1
+	SPEED_DEFAULT = 3
+	SPEED_FASTEST = 10
+)
+
 func (this *Attributes) SetSpeed(speed int) error {
 	return translateError(C.liq_set_speed(this.p, C.int(speed)))
 }
diff --git a/imagequant.go b/imagequant.go
index 9c42c23..77a0b52 100644
--- a/imagequant.go
+++ b/imagequant.go
@@ -58,9 +58,3 @@ func GetLibraryVersion() int {
 func GetLibraryVersionString() string {
 	return C.GoString(C.liqVersionString())
 }
-
-const (
-	SPEED_SLOWEST = 1
-	SPEED_DEFAULT = 3
-	SPEED_FASTEST = 10
-)