diff --git a/MXSegmentedPager/MXPagerView.m b/MXSegmentedPager/MXPagerView.m
index 4846036fc..a5469ba37 100644
--- a/MXSegmentedPager/MXPagerView.m
+++ b/MXSegmentedPager/MXPagerView.m
@@ -59,7 +59,7 @@ - (void)layoutSubviews {
     
     CGRect frame = self.bounds;
     //Layout content view
-    frame.origin = CGPointMake(0, 0);
+    frame.origin = CGPointZero;
     frame.size.width += self.gutterWidth;
     self.contentView.frame = frame;
     
@@ -69,15 +69,11 @@ - (void)layoutSubviews {
     [self setContentIndex:_index animated:NO];
     
     //Layout loaded pages
+    frame.size = self.bounds.size;
     for (NSNumber *key in self.pages) {
-        NSInteger index = [key integerValue];
         UIView *page = self.pages[key];
-    
-        page.frame = (CGRect) {
-            .origin.x   = frame.size.width * index,
-            .origin.y   = 0,
-            .size       = self.bounds.size
-        };
+        frame.origin.x = self.contentView.bounds.size.width * [key integerValue];
+        page.frame = frame;
     }
     
     [super layoutSubviews];
@@ -137,6 +133,8 @@ - (__kindof UIView *)dequeueReusablePageWithIdentifier:(NSString *)identifier {
     }
     
     id builder = self.registration[identifier];
+    NSAssert(builder, @"unable to dequeue a page with identifier %@ - must register a nib or a class for the identifier", identifier);
+    
     UIView *page = nil;
     
     if ([builder isKindOfClass:[UINib class]]) {
@@ -146,8 +144,6 @@ - (__kindof UIView *)dequeueReusablePageWithIdentifier:(NSString *)identifier {
         page = [[NSClassFromString(builder) alloc] init];
     }
     
-    NSAssert(page, @"unable to dequeue a page with identifier %@ - must register a nib or a class for the identifier", identifier);
-    
     page.reuseIdentifier = identifier;
     [self.reuseQueue addObject:page];
     [page prepareForReuse];
@@ -264,11 +260,10 @@ - (void) loadPageAtIndex:(NSInteger) index {
                 UIView *page = [self.dataSource pagerView:self viewForPageAtIndex:index];
                 [self.contentView addSubview:page];
                 [self.pages setObject:page forKey:key];
-                page.frame = (CGRect) {
-                    .origin.x   = self.contentView.bounds.size.width * index,
-                    .origin.y   = 0.f,
-                    .size       = self.bounds.size
-                };
+                //Layout page
+                CGRect frame = self.bounds;
+                frame.origin = CGPointMake(self.contentView.bounds.size.width * index, 0);
+                page.frame = frame;
             }
         }
     };
diff --git a/MXSegmentedPager/MXSegmentedPager.h b/MXSegmentedPager/MXSegmentedPager.h
index 2ab23c4a0..b58f4d6f2 100644
--- a/MXSegmentedPager/MXSegmentedPager.h
+++ b/MXSegmentedPager/MXSegmentedPager.h
@@ -56,7 +56,7 @@ typedef void (^MXProgressBlock) (CGFloat progress);
  @param segmentedPager A segmented-pager object informing the delegate about the impending selection.
  @param view           The selected page view.
  */
-- (void) segmentedPager:(MXSegmentedPager*)segmentedPager didSelectView:(UIView*)view;
+- (void) segmentedPager:(nonnull MXSegmentedPager*)segmentedPager didSelectView:(nonnull UIView*)view;
 
 /**
  Tells the delegate that a specified title is about to be selected.
@@ -64,7 +64,7 @@ typedef void (^MXProgressBlock) (CGFloat progress);
  @param segmentedPager A segmented-pager object informing the delegate about the impending selection.
  @param title          The selected page title.
  */
-- (void) segmentedPager:(MXSegmentedPager*)segmentedPager didSelectViewWithTitle:(NSString*)title;
+- (void) segmentedPager:(nonnull MXSegmentedPager*)segmentedPager didSelectViewWithTitle:(nonnull NSString*)title;
 
 /**
  Tells the delegate that a specified index is about to be selected.
@@ -72,7 +72,7 @@ typedef void (^MXProgressBlock) (CGFloat progress);
  @param segmentedPager A segmented-pager object informing the delegate about the impending selection.
  @param index          The selected page index.
  */
-- (void) segmentedPager:(MXSegmentedPager*)segmentedPager didSelectViewWithIndex:(NSInteger)index;
+- (void) segmentedPager:(nonnull MXSegmentedPager*)segmentedPager didSelectViewWithIndex:(NSInteger)index;
 
 /**
  Asks the delegate to return the height of the segmented control in the segmented-pager.
@@ -81,7 +81,7 @@ typedef void (^MXProgressBlock) (CGFloat progress);
  
  @return A nonnegative floating-point value that specifies the height (in points) that segmented-control should be.
  */
-- (CGFloat) heightForSegmentedControlInSegmentedPager:(MXSegmentedPager*)segmentedPager;
+- (CGFloat) heightForSegmentedControlInSegmentedPager:(nonnull MXSegmentedPager*)segmentedPager;
 
 @end
 
@@ -101,7 +101,7 @@ typedef void (^MXProgressBlock) (CGFloat progress);
  
  @return The number of pages in segmented-pager.
  */
-- (NSInteger) numberOfPagesInSegmentedPager:(MXSegmentedPager *)segmentedPager;
+- (NSInteger) numberOfPagesInSegmentedPager:(nonnull MXSegmentedPager *)segmentedPager;
 
 /**
  Asks the data source for a view to insert in a particular page of the segmented-pager.
@@ -111,7 +111,7 @@ typedef void (^MXProgressBlock) (CGFloat progress);
  
  @return An object inheriting from UIView that the segmented-pager can use for the specified page.
  */
-- (UIView*) segmentedPager:(MXSegmentedPager*)segmentedPager viewForPageAtIndex:(NSInteger)index;
+- (nonnull __kindof UIView*) segmentedPager:(nonnull MXSegmentedPager*)segmentedPager viewForPageAtIndex:(NSInteger)index;
 
 @optional
 
@@ -123,7 +123,7 @@ typedef void (^MXProgressBlock) (CGFloat progress);
  
  @return The NSString title of the page in segmented-pager.
  */
-- (NSString*) segmentedPager:(MXSegmentedPager*)segmentedPager titleForSectionAtIndex:(NSInteger)index;
+- (nonnull NSString*) segmentedPager:(nonnull MXSegmentedPager*)segmentedPager titleForSectionAtIndex:(NSInteger)index;
 
 /**
  Asks the data source for a title to assign to a particular page of the segmented-pager. The title will be used depending on the HMSegmentedControlType you have choosen.
@@ -133,7 +133,7 @@ typedef void (^MXProgressBlock) (CGFloat progress);
  
  @return The NSAttributedString title of the page in segmented-pager.
  */
-- (NSAttributedString*) segmentedPager:(MXSegmentedPager*)segmentedPager attributedTitleForSectionAtIndex:(NSInteger)index;
+- (nonnull NSAttributedString*) segmentedPager:(nonnull MXSegmentedPager*)segmentedPager attributedTitleForSectionAtIndex:(NSInteger)index;
 
 /**
  Asks the data source for a image to assign to a particular page of the segmented-pager. The image will be used depending on the HMSegmentedControlType you have choosen.
@@ -143,7 +143,7 @@ typedef void (^MXProgressBlock) (CGFloat progress);
  
  @return The image of the page in segmented-pager.
  */
-- (UIImage*) segmentedPager:(MXSegmentedPager*)segmentedPager imageForSectionAtIndex:(NSInteger)index;
+- (nonnull UIImage*) segmentedPager:(nonnull MXSegmentedPager*)segmentedPager imageForSectionAtIndex:(NSInteger)index;
 
 @end
 
@@ -155,32 +155,32 @@ typedef void (^MXProgressBlock) (CGFloat progress);
 /**
  Delegate instance that adopt the MXSegmentedPagerDelegate.
  */
-@property (nonatomic, assign) id<MXSegmentedPagerDelegate> delegate;
+@property (nonatomic, weak) id<MXSegmentedPagerDelegate> delegate;
 
 /**
  Data source instance that adopt the MXSegmentedPagerDataSource.
  */
-@property (nonatomic, assign) id<MXSegmentedPagerDataSource> dataSource;
+@property (nonatomic, weak) id<MXSegmentedPagerDataSource> dataSource;
 
 /**
  The segmented control. cf. [HMSegmentedControl](http://cocoadocs.org/docsets/HMSegmentedControl/1.5/) for customazation.
  */
-@property (nonatomic, readonly) HMSegmentedControl* segmentedControl;
+@property (nonatomic, readonly, nonnull) HMSegmentedControl* segmentedControl;
 
 /**
  The segmented control position option.
  */
-@property (nonatomic, assign) MXSegmentedControlPosition segmentedControlPosition;
+@property (nonatomic) MXSegmentedControlPosition segmentedControlPosition;
 
 /**
  The pager. The pager will be placed above or below the segmented control depending on the segmentedControlPosition property.
  */
-@property (nonatomic, readonly) MXPagerView* pager;
+@property (nonatomic, readonly, nonnull) MXPagerView* pager;
 
 /**
  The padding from the top, left, right, and bottom of the segmentedControl
  */
-@property (nonatomic, assign) UIEdgeInsets segmentedControlEdgeInsets;
+@property (nonatomic) UIEdgeInsets segmentedControlEdgeInsets;
 
 /**
  Reloads everything from scratch. redisplays pages.
@@ -205,17 +205,17 @@ typedef void (^MXProgressBlock) (CGFloat progress);
 /**
  The parallax header. cf. [VGParallaxHeader](http://cocoadocs.org/docsets/VGParallaxHeader/0.0.6/) for more details.
  */
-@property (nonatomic, strong, readonly) VGParallaxHeader *parallaxHeader;
+@property (nonatomic, strong, readonly, nonnull) VGParallaxHeader *parallaxHeader;
 
 /**
  The minimum header height, the header won't scroll below this value. By default, the minimum height is set to 0.
  */
-@property (nonatomic, assign) CGFloat minimumHeaderHeight;
+@property (nonatomic) CGFloat minimumHeaderHeight;
 
 /**
  The progress block called when scroll is progressing.
  */
-@property (nonatomic, strong) MXProgressBlock progressBlock;
+@property (nonatomic, strong, nullable) MXProgressBlock progressBlock;
 
 /**
  Sets the parallax header view.
@@ -224,7 +224,7 @@ typedef void (^MXProgressBlock) (CGFloat progress);
  @param mode   The parallax header mode. cf. [VGParallaxHeader](http://cocoadocs.org/docsets/VGParallaxHeader/0.0.6/) for more details.
  @param height The header height.
  */
-- (void)setParallaxHeaderView:(UIView *)view
+- (void)setParallaxHeaderView:(nonnull __kindof UIView *)view
                          mode:(VGParallaxHeaderMode)mode
                        height:(CGFloat)height;
 @end
@@ -243,6 +243,6 @@ typedef void (^MXProgressBlock) (CGFloat progress);
  
  @return YES to allow segmented-pager and view to scroll together. The default implementation returns YES.
  */
-- (BOOL) segmentedPager:(MXSegmentedPager *)segmentedPager shouldScrollWithView:(UIView*)view;
+- (BOOL) segmentedPager:(nonnull MXSegmentedPager *)segmentedPager shouldScrollWithView:(nonnull __kindof UIView*)view;
 
 @end
diff --git a/MXSegmentedPager/MXSegmentedPager.m b/MXSegmentedPager/MXSegmentedPager.m
index a40ee268b..0d63b64f3 100644
--- a/MXSegmentedPager/MXSegmentedPager.m
+++ b/MXSegmentedPager/MXSegmentedPager.m
@@ -56,13 +56,12 @@ - (void)layoutSubviews {
         [self reloadData];
     }
     
+    CGRect frame = self.bounds;
     //Layout content view
-    self.contentView.frame = (CGRect) {
-        .origin = CGPointZero,
-        .size   = self.bounds.size
-    };
+    frame.origin = CGPointZero;
+    self.contentView.frame = frame;
     
-    CGRect frame;
+    //Layout control
     frame.origin = (self.segmentedControlPosition == MXSegmentedControlPositionTop)?
     CGPointMake(self.segmentedControlEdgeInsets.left, self.segmentedControlEdgeInsets.top) :
     CGPointMake(self.segmentedControlEdgeInsets.left, self.bounds.size.height - _controlHeight - self.segmentedControlEdgeInsets.bottom);
diff --git a/MXSegmentedPager/MXSegmentedPagerController.h b/MXSegmentedPager/MXSegmentedPagerController.h
index 54b1102d1..8e8edc177 100644
--- a/MXSegmentedPager/MXSegmentedPagerController.h
+++ b/MXSegmentedPager/MXSegmentedPagerController.h
@@ -36,7 +36,7 @@
  
  @return An object inheriting from UIViewController that the segmented-pager can use for the specified page.
  */
-- (UIViewController *)segmentedPager:(MXSegmentedPager *)segmentedPager viewControllerForPageAtIndex:(NSInteger)index;
+- (nonnull __kindof UIViewController *)segmentedPager:(nonnull MXSegmentedPager *)segmentedPager viewControllerForPageAtIndex:(NSInteger)index;
 
 /**
  Asks the data source for a segue identifier to insert in a particular page of the segmented-pager.
@@ -46,7 +46,7 @@
  
  @return The segue identifier that the segmented-pager can use for the specified page.
  */
-- (NSString *)segmentedPager:(MXSegmentedPager *)segmentedPager segueIdentifierForPageAtIndex:(NSInteger)index;
+- (nonnull NSString *)segmentedPager:(nonnull MXSegmentedPager *)segmentedPager segueIdentifierForPageAtIndex:(NSInteger)index;
 
 @end
 
@@ -58,14 +58,14 @@
 /**
  Returns the segmengted-pager view managed by the controller object.
  */
-@property (nonatomic, strong) MXSegmentedPager *segmentedPager;
+@property (nonatomic, strong, readonly, nonnull) MXSegmentedPager *segmentedPager;
 
 @end
 
 /**
  Default string identifier format to be applied to segues on a storyboard
  */
-extern NSString* const MXSeguePageIdentifierFormat;  // @"mx_page_%ld"
+extern NSString* _Nonnull const MXSeguePageIdentifierFormat;  // @"mx_page_%ld"
 
 /**
  The MXPageSegue class creates a segue object to get pages from storyboard.
diff --git a/MXSegmentedPager/MXSegmentedPagerController.m b/MXSegmentedPager/MXSegmentedPagerController.m
index 81ea36895..bc35f2c01 100644
--- a/MXSegmentedPager/MXSegmentedPagerController.m
+++ b/MXSegmentedPager/MXSegmentedPagerController.m
@@ -24,20 +24,17 @@
 
 @interface MXSegmentedPagerController ()
 @property (nonatomic,weak) UIViewController *pageViewController;
-@property (nonatomic,assign) NSInteger pageIndex;
+@property (nonatomic) NSInteger pageIndex;
 @end
 
 @implementation MXSegmentedPagerController
 
+@synthesize segmentedPager = _segmentedPager;
+
 - (void)loadView {
     self.view = self.segmentedPager;
 }
 
-- (void)didReceiveMemoryWarning {
-    [super didReceiveMemoryWarning];
-    self.segmentedPager = nil;
-}
-
 #pragma mark Properties
 
 - (UIView *)segmentedPager {