diff --git a/src/context.rs b/src/context.rs
index 8a9ac3a..7009e6b 100644
--- a/src/context.rs
+++ b/src/context.rs
@@ -9,9 +9,9 @@
 
 use base::CGFloat;
 use color_space::CGColorSpace;
-use core_foundation::base::{CFRelease, CFRetain, CFTypeID, CFTypeRef, TCFType};
+use core_foundation::base::{CFRelease, CFRetain, CFTypeID};
 use libc::{c_void, c_int, size_t};
-use std::mem;
+
 use std::ptr;
 use std::slice;
 use geometry::CGRect;
@@ -29,67 +29,22 @@ pub enum CGTextDrawingMode {
     CGTextClip
 }
 
-// This is an enum due to zero-sized types warnings.
-// For more details see https://github.com/rust-lang/rust/issues/27303
-pub enum __CGContext {}
-
-pub type CGContextRef = *const __CGContext;
-
-pub struct CGContext {
-    obj: CGContextRef,
+foreign_type! {
+    #[doc(hidden)]
+    type CType = ::sys::CGContext;
+    fn drop = |cs| CFRelease(cs as *mut _);
+    fn clone = |p| CFRetain(p as *const _) as *mut _;
+    pub struct CGContext;
+    pub struct CGContextRef;
 }
 
-impl Drop for CGContext {
-    fn drop(&mut self) {
-        unsafe {
-            CFRelease(self.as_CFTypeRef())
-        }
-    }
-}
-
-impl Clone for CGContext {
-    fn clone(&self) -> CGContext {
-        unsafe {
-            TCFType::wrap_under_get_rule(self.as_concrete_TypeRef())
-        }
-    }
-}
-
-impl TCFType<CGContextRef> for CGContext {
-    #[inline]
-    fn as_concrete_TypeRef(&self) -> CGContextRef {
-        self.obj
-    }
-
-    #[inline]
-    unsafe fn wrap_under_get_rule(reference: CGContextRef) -> CGContext {
-        let reference: CGContextRef = mem::transmute(CFRetain(mem::transmute(reference)));
-        TCFType::wrap_under_create_rule(reference)
-    }
-
-    #[inline]
-    fn as_CFTypeRef(&self) -> CFTypeRef {
-        unsafe {
-            mem::transmute(self.as_concrete_TypeRef())
-        }
-    }
-
-    #[inline]
-    unsafe fn wrap_under_create_rule(obj: CGContextRef) -> CGContext {
-        CGContext {
-            obj: obj,
-        }
-    }
-
-    #[inline]
-    fn type_id() -> CFTypeID {
+impl CGContext {
+    pub fn type_id() -> CFTypeID {
         unsafe {
             CGContextGetTypeID()
         }
     }
-}
 
-impl CGContext {
     pub fn create_bitmap_context(data: Option<*mut c_void>,
                                  width: size_t,
                                  height: size_t,
@@ -107,116 +62,116 @@ impl CGContext {
                                                space.as_ptr(),
                                                bitmap_info);
             assert!(!result.is_null());
-            TCFType::wrap_under_create_rule(result)
+            Self::from_ptr(result)
         }
     }
 
     pub fn data(&mut self) -> &mut [u8] {
         unsafe {
             slice::from_raw_parts_mut(
-                    CGBitmapContextGetData(self.as_concrete_TypeRef()) as *mut u8,
+                    CGBitmapContextGetData(self.as_ptr()) as *mut u8,
                     (self.height() * self.bytes_per_row()) as usize)
         }
     }
 
     pub fn width(&self) -> size_t {
         unsafe {
-            CGBitmapContextGetWidth(self.as_concrete_TypeRef())
+            CGBitmapContextGetWidth(self.as_ptr())
         }
     }
 
     pub fn height(&self) -> size_t {
         unsafe {
-            CGBitmapContextGetHeight(self.as_concrete_TypeRef())
+            CGBitmapContextGetHeight(self.as_ptr())
         }
     }
 
     pub fn bytes_per_row(&self) -> size_t {
         unsafe {
-            CGBitmapContextGetBytesPerRow(self.as_concrete_TypeRef())
+            CGBitmapContextGetBytesPerRow(self.as_ptr())
         }
     }
 
     pub fn set_rgb_fill_color(&self, red: CGFloat, green: CGFloat, blue: CGFloat, alpha: CGFloat) {
         unsafe {
-            CGContextSetRGBFillColor(self.as_concrete_TypeRef(), red, green, blue, alpha)
+            CGContextSetRGBFillColor(self.as_ptr(), red, green, blue, alpha)
         }
     }
 
     pub fn set_allows_font_smoothing(&self, allows_font_smoothing: bool) {
         unsafe {
-            CGContextSetAllowsFontSmoothing(self.as_concrete_TypeRef(), allows_font_smoothing)
+            CGContextSetAllowsFontSmoothing(self.as_ptr(), allows_font_smoothing)
         }
     }
 
     pub fn set_font_smoothing_style(&self, style: i32) {
         unsafe {
-            CGContextSetFontSmoothingStyle(self.as_concrete_TypeRef(), style as _);
+            CGContextSetFontSmoothingStyle(self.as_ptr(), style as _);
         }
     }
 
     pub fn set_should_smooth_fonts(&self, should_smooth_fonts: bool) {
         unsafe {
-            CGContextSetShouldSmoothFonts(self.as_concrete_TypeRef(), should_smooth_fonts)
+            CGContextSetShouldSmoothFonts(self.as_ptr(), should_smooth_fonts)
         }
     }
 
     pub fn set_allows_antialiasing(&self, allows_antialiasing: bool) {
         unsafe {
-            CGContextSetAllowsAntialiasing(self.as_concrete_TypeRef(), allows_antialiasing)
+            CGContextSetAllowsAntialiasing(self.as_ptr(), allows_antialiasing)
         }
     }
 
     pub fn set_should_antialias(&self, should_antialias: bool) {
         unsafe {
-            CGContextSetShouldAntialias(self.as_concrete_TypeRef(), should_antialias)
+            CGContextSetShouldAntialias(self.as_ptr(), should_antialias)
         }
     }
 
     pub fn set_allows_font_subpixel_quantization(&self, allows_font_subpixel_quantization: bool) {
         unsafe {
-            CGContextSetAllowsFontSubpixelQuantization(self.as_concrete_TypeRef(), allows_font_subpixel_quantization)
+            CGContextSetAllowsFontSubpixelQuantization(self.as_ptr(), allows_font_subpixel_quantization)
         }
     }
 
     pub fn set_should_subpixel_quantize_fonts(&self, should_subpixel_quantize_fonts: bool) {
         unsafe {
-            CGContextSetShouldSubpixelQuantizeFonts(self.as_concrete_TypeRef(), should_subpixel_quantize_fonts)
+            CGContextSetShouldSubpixelQuantizeFonts(self.as_ptr(), should_subpixel_quantize_fonts)
         }
     }
 
     pub fn set_allows_font_subpixel_positioning(&self, allows_font_subpixel_positioning: bool) {
         unsafe {
-            CGContextSetAllowsFontSubpixelPositioning(self.as_concrete_TypeRef(), allows_font_subpixel_positioning)
+            CGContextSetAllowsFontSubpixelPositioning(self.as_ptr(), allows_font_subpixel_positioning)
         }
     }
 
     pub fn set_should_subpixel_position_fonts(&self, should_subpixel_position_fonts: bool) {
         unsafe {
-            CGContextSetShouldSubpixelPositionFonts(self.as_concrete_TypeRef(), should_subpixel_position_fonts)
+            CGContextSetShouldSubpixelPositionFonts(self.as_ptr(), should_subpixel_position_fonts)
         }
     }
 
     pub fn set_text_drawing_mode(&self, mode: CGTextDrawingMode) {
         unsafe {
-            CGContextSetTextDrawingMode(self.as_concrete_TypeRef(), mode)
+            CGContextSetTextDrawingMode(self.as_ptr(), mode)
         }
     }
 
     pub fn fill_rect(&self, rect: CGRect) {
         unsafe {
-            CGContextFillRect(self.as_concrete_TypeRef(), rect)
+            CGContextFillRect(self.as_ptr(), rect)
         }
     }
 
     pub fn draw_image(&self, rect: CGRect, image: &CGImage) {
         unsafe {
-            CGContextDrawImage(self.as_concrete_TypeRef(), rect, image.as_ptr());
+            CGContextDrawImage(self.as_ptr(), rect, image.as_ptr());
         }
     }
 
     pub fn create_image(&self) -> Option<CGImage> {
-        let image = unsafe { CGBitmapContextCreateImage(self.as_concrete_TypeRef()) };
+        let image = unsafe { CGBitmapContextCreateImage(self.as_ptr()) };
         if !image.is_null() {
             Some(unsafe { CGImage::from_ptr(image) })
         } else {
@@ -258,34 +213,34 @@ extern {
                              bytesPerRow: size_t,
                              space: ::sys::CGColorSpaceRef,
                              bitmapInfo: u32)
-                             -> CGContextRef;
-    fn CGBitmapContextGetData(context: CGContextRef) -> *mut c_void;
-    fn CGBitmapContextGetWidth(context: CGContextRef) -> size_t;
-    fn CGBitmapContextGetHeight(context: CGContextRef) -> size_t;
-    fn CGBitmapContextGetBytesPerRow(context: CGContextRef) -> size_t;
-    fn CGBitmapContextCreateImage(context: CGContextRef) -> ::sys::CGImageRef;
+                             -> ::sys::CGContextRef;
+    fn CGBitmapContextGetData(context: ::sys::CGContextRef) -> *mut c_void;
+    fn CGBitmapContextGetWidth(context: ::sys::CGContextRef) -> size_t;
+    fn CGBitmapContextGetHeight(context: ::sys::CGContextRef) -> size_t;
+    fn CGBitmapContextGetBytesPerRow(context: ::sys::CGContextRef) -> size_t;
+    fn CGBitmapContextCreateImage(context: ::sys::CGContextRef) -> ::sys::CGImageRef;
     fn CGContextGetTypeID() -> CFTypeID;
-    fn CGContextSetAllowsFontSmoothing(c: CGContextRef, allowsFontSmoothing: bool);
-    fn CGContextSetShouldSmoothFonts(c: CGContextRef, shouldSmoothFonts: bool);
-    fn CGContextSetFontSmoothingStyle(c: CGContextRef, style: c_int);
-    fn CGContextSetAllowsAntialiasing(c: CGContextRef, allowsAntialiasing: bool);
-    fn CGContextSetShouldAntialias(c: CGContextRef, shouldAntialias: bool);
-    fn CGContextSetAllowsFontSubpixelQuantization(c: CGContextRef,
+    fn CGContextSetAllowsFontSmoothing(c: ::sys::CGContextRef, allowsFontSmoothing: bool);
+    fn CGContextSetShouldSmoothFonts(c: ::sys::CGContextRef, shouldSmoothFonts: bool);
+    fn CGContextSetFontSmoothingStyle(c: ::sys::CGContextRef, style: c_int);
+    fn CGContextSetAllowsAntialiasing(c: ::sys::CGContextRef, allowsAntialiasing: bool);
+    fn CGContextSetShouldAntialias(c: ::sys::CGContextRef, shouldAntialias: bool);
+    fn CGContextSetAllowsFontSubpixelQuantization(c: ::sys::CGContextRef,
                                                   allowsFontSubpixelQuantization: bool);
-    fn CGContextSetShouldSubpixelQuantizeFonts(c: CGContextRef,
+    fn CGContextSetShouldSubpixelQuantizeFonts(c: ::sys::CGContextRef,
                                                shouldSubpixelQuantizeFonts: bool);
-    fn CGContextSetAllowsFontSubpixelPositioning(c: CGContextRef,
+    fn CGContextSetAllowsFontSubpixelPositioning(c: ::sys::CGContextRef,
                                                  allowsFontSubpixelPositioning: bool);
-    fn CGContextSetShouldSubpixelPositionFonts(c: CGContextRef,
+    fn CGContextSetShouldSubpixelPositionFonts(c: ::sys::CGContextRef,
                                                shouldSubpixelPositionFonts: bool);
-    fn CGContextSetTextDrawingMode(c: CGContextRef, mode: CGTextDrawingMode);
-    fn CGContextSetRGBFillColor(context: CGContextRef,
+    fn CGContextSetTextDrawingMode(c: ::sys::CGContextRef, mode: CGTextDrawingMode);
+    fn CGContextSetRGBFillColor(context: ::sys::CGContextRef,
                                 red: CGFloat,
                                 green: CGFloat,
                                 blue: CGFloat,
                                 alpha: CGFloat);
-    fn CGContextFillRect(context: CGContextRef,
+    fn CGContextFillRect(context: ::sys::CGContextRef,
                          rect: CGRect);
-    fn CGContextDrawImage(c: CGContextRef, rect: CGRect, image: ::sys::CGImageRef);
+    fn CGContextDrawImage(c: ::sys::CGContextRef, rect: CGRect, image: ::sys::CGImageRef);
 }
 
diff --git a/src/sys.rs b/src/sys.rs
index e586073..e7dd44f 100644
--- a/src/sys.rs
+++ b/src/sys.rs
@@ -13,4 +13,7 @@ pub type CGFontRef = *mut CGFont;
 pub enum CGEvent {}
 pub type CGEventRef = *mut CGEvent;
 
+pub enum CGContext {}
+pub type CGContextRef = *mut CGContext;
+