@@ -25,10 +25,12 @@
 
 #import "OFObject.h"
 #import "OFCollection.h"
 #import "OFSerialization.h"
 
+OF_ASSUME_NONNULL_BEGIN
+
 /*! @file */
 
 @class OFArray OF_GENERIC(ObjectType);
 
 #ifdef OF_HAVE_BLOCKS
@@ -103,11 +105,11 @@
  *
  * @param objects An array of objects for the set
  * @param count The number of objects in the specified array
  * @return A new, autoreleased set with the specified objects
  */
-+ (instancetype)setWithObjects: (ObjectType const*)objects
++ (instancetype)setWithObjects: (__nonnull ObjectType const *__nonnull)objects
 			 count: (size_t)count;
 
 /*!
  * @brief Initializes an already allocated set with the specified set.
  *
@@ -137,11 +139,11 @@
  *
  * @param objects An array of objects for the set
  * @param count The number of objects in the specified array
  * @return An initialized set with the specified objects
  */
-- initWithObjects: (ObjectType const*)objects
+- initWithObjects: (__nonnull ObjectType const *__nonnull)objects
 	    count: (size_t)count;
 
 /*!
  * @brief Initializes an already allocated set with the specified object and
  *	  va_list.
@@ -215,11 +217,11 @@
  *	  object.
  *
  * @param object The object which is checked for being in the set
  * @return A boolean whether the set contains the specified object
  */
-- (bool)containsObject: (ObjectType)object;
+- (bool)containsObject: (nullable ObjectType)object;
 
 /*!
  * @brief Returns an OFEnumerator to enumerate through all objects of the set.
  *
  * @returns An OFEnumerator to enumerate through all objects of the set
@@ -246,7 +248,9 @@
 #endif
 @end
 #if !defined(OF_HAVE_GENERICS) && !defined(DOXYGEN)
 # undef ObjectType
 #endif
+
+OF_ASSUME_NONNULL_END
 
 #import "OFMutableSet.h"