diff --git a/Code/ObjectMapping/RKObjectMapping.h b/Code/ObjectMapping/RKObjectMapping.h
index aad7a6b9..260794e5 100644
--- a/Code/ObjectMapping/RKObjectMapping.h
+++ b/Code/ObjectMapping/RKObjectMapping.h
@@ -131,6 +131,8 @@ relationship. Relationships are processed using an object mapping as well.
  */
 + (id)mappingForClass:(Class)objectClass;
 
+- (id)initWithClass:(Class)objectClass; // Designated initializer
+
 /**
  Returns an object mapping useful for configuring a serialization mapping. The object
  class is configured as NSMutableDictionary
diff --git a/Code/ObjectMapping/RKObjectMapping.m b/Code/ObjectMapping/RKObjectMapping.m
index a3415090..ca6370d0 100644
--- a/Code/ObjectMapping/RKObjectMapping.m
+++ b/Code/ObjectMapping/RKObjectMapping.m
@@ -48,9 +48,7 @@ NSString * const RKObjectMappingNestingAttributeKeyName = @"<RK_NESTING_ATTRIBUT
 
 + (id)mappingForClass:(Class)objectClass
 {
-    RKObjectMapping *mapping = [self new];
-    mapping.objectClass = objectClass;
-    return mapping;
+    return [[self alloc] initWithClass:objectClass];
 }
 
 + (id)requestMapping
@@ -58,10 +56,11 @@ NSString * const RKObjectMappingNestingAttributeKeyName = @"<RK_NESTING_ATTRIBUT
     return [self mappingForClass:[NSMutableDictionary class]];
 }
 
-- (id)init
+- (id)initWithClass:(Class)objectClass
 {
     self = [super init];
     if (self) {
+        self.objectClass = objectClass;
         self.mutablePropertyMappings = [NSMutableArray new];
         self.setDefaultValueForMissingAttributes = NO;
         self.setNilForMissingRelationships = NO;