diff --git a/example/freetype/main.go b/example/freetype/main.go
index 4452286..c7e45b1 100644
--- a/example/freetype/main.go
+++ b/example/freetype/main.go
@@ -21,8 +21,8 @@ import (
 var (
 	dpi      = flag.Int("dpi", 72, "screen resolution in Dots Per Inch")
 	fontfile = flag.String("fontfile", "../../luxi-fonts/luxisr.ttf", "filename of the ttf font")
-	size     = flag.Float("size", 12, "font size in points")
-	spacing  = flag.Float("spacing", 1.5, "line spacing (e.g. 2 means double spaced)")
+	size     = flag.Float64("size", 12, "font size in points")
+	spacing  = flag.Float64("spacing", 1.5, "line spacing (e.g. 2 means double spaced)")
 	wonb     = flag.Bool("whiteonblack", false, "white text on a black background")
 )
 
diff --git a/example/gamma/main.go b/example/gamma/main.go
index 9db9646..b1839a3 100644
--- a/example/gamma/main.go
+++ b/example/gamma/main.go
@@ -55,7 +55,7 @@ func main() {
 	draw.Draw(rgba, image.Rect(0, h/2, w, h), image.White, image.ZP)
 	mask := image.NewAlpha(50, 50)
 	painter := raster.NewAlphaSrcPainter(mask)
-	gammas := []float{1.0 / 10.0, 1.0 / 3.0, 1.0 / 2.0, 2.0 / 3.0, 4.0 / 5.0, 1.0, 5.0 / 4.0, 3.0 / 2.0, 2.0, 3.0, 10.0}
+	gammas := []float64{1.0 / 10.0, 1.0 / 3.0, 1.0 / 2.0, 2.0 / 3.0, 4.0 / 5.0, 1.0, 5.0 / 4.0, 3.0 / 2.0, 2.0, 3.0, 10.0}
 	for i, g := range gammas {
 		clear(mask)
 		r.Rasterize(raster.NewGammaCorrectionPainter(painter, g))
diff --git a/freetype/freetype.go b/freetype/freetype.go
index b35e769..d5db987 100644
--- a/freetype/freetype.go
+++ b/freetype/freetype.go
@@ -69,7 +69,7 @@ type Context struct {
 	// which equals 384 fixed point units per 256 FUnits.
 	// To check this, 1 em * 2048 FUnits per em * 384 fixed point units per 256 FUnits
 	// equals 3072 fixed point units.
-	fontSize float
+	fontSize float64
 	dpi      int
 	upe      int
 	scale    int
@@ -97,8 +97,8 @@ func (c *Context) FUnitToPixelRU(x int) int {
 
 // PointToFix32 converts the given number of points (as in ``a 12 point font'')
 // into fixed point units.
-func (c *Context) PointToFix32(x float) raster.Fix32 {
-	return raster.Fix32(x * float(c.dpi) * (256.0 / 72.0))
+func (c *Context) PointToFix32(x float64) raster.Fix32 {
+	return raster.Fix32(x * float64(c.dpi) * (256.0 / 72.0))
 }
 
 // drawContour draws the given closed contour with the given offset.
@@ -243,7 +243,7 @@ func (c *Context) DrawString(s string, p raster.Point) (raster.Point, os.Error)
 // recalc recalculates scale and bounds values from the font size, screen
 // resolution and font metrics, and invalidates the glyph cache.
 func (c *Context) recalc() {
-	c.scale = int((c.fontSize * float(c.dpi) * 256 * 256) / (float(c.upe) * 72))
+	c.scale = int((c.fontSize * float64(c.dpi) * 256 * 256) / (float64(c.upe) * 72))
 	if c.font == nil {
 		c.r.SetBounds(0, 0)
 	} else {
@@ -283,7 +283,7 @@ func (c *Context) SetFont(font *truetype.Font) {
 }
 
 // SetFontSize sets the font size in points (as in ``a 12 point font'').
-func (c *Context) SetFontSize(fontSize float) {
+func (c *Context) SetFontSize(fontSize float64) {
 	if c.fontSize == fontSize {
 		return
 	}
diff --git a/freetype/raster/paint.go b/freetype/raster/paint.go
index c924115..7c0ad89 100644
--- a/freetype/raster/paint.go
+++ b/freetype/raster/paint.go
@@ -273,23 +273,22 @@ func (g *GammaCorrectionPainter) Paint(ss []Span, done bool) {
 }
 
 // SetGamma sets the gamma value.
-func (g *GammaCorrectionPainter) SetGamma(gamma float) {
+func (g *GammaCorrectionPainter) SetGamma(gamma float64) {
 	if gamma == 1.0 {
 		g.gammaIsOne = true
 		return
 	}
 	g.gammaIsOne = false
-	gamma64 := float64(gamma)
 	for i := 0; i < 256; i++ {
 		a := float64(i) / 0xff
-		a = math.Pow(a, gamma64)
+		a = math.Pow(a, gamma)
 		g.a[i] = uint16(0xffff * a)
 	}
 }
 
 // NewGammaCorrectionPainter creates a new GammaCorrectionPainter that wraps
 // the given Painter.
-func NewGammaCorrectionPainter(p Painter, gamma float) *GammaCorrectionPainter {
+func NewGammaCorrectionPainter(p Painter, gamma float64) *GammaCorrectionPainter {
 	g := &GammaCorrectionPainter{Painter: p}
 	g.SetGamma(gamma)
 	return g