diff --git a/Libraries/Geolocation/RCTLocationObserver.m b/Libraries/Geolocation/RCTLocationObserver.m
index 5d56caccb..3e864657b 100644
--- a/Libraries/Geolocation/RCTLocationObserver.m
+++ b/Libraries/Geolocation/RCTLocationObserver.m
@@ -163,12 +163,12 @@ RCT_EXPORT_MODULE()
 
 #pragma mark - Public API
 
-RCT_EXPORT_METHOD(startObserving:(NSDictionary *)optionsJSON)
+RCT_EXPORT_METHOD(startObserving:(RCTLocationOptions)options)
 {
   [self checkLocationConfig];
 
   // Select best options
-  _observerOptions = [RCTConvert RCTLocationOptions:optionsJSON];
+  _observerOptions = options;
   for (RCTLocationRequest *request in _pendingRequests) {
     _observerOptions.accuracy = MIN(_observerOptions.accuracy, request.options.accuracy);
   }
@@ -189,7 +189,7 @@ RCT_EXPORT_METHOD(stopObserving)
   }
 }
 
-RCT_EXPORT_METHOD(getCurrentPosition:(NSDictionary *)optionsJSON
+RCT_EXPORT_METHOD(getCurrentPosition:(RCTLocationOptions)options
                   withSuccessCallback:(RCTResponseSenderBlock)successBlock
                   errorCallback:(RCTResponseSenderBlock)errorBlock)
 {
@@ -219,7 +219,6 @@ RCT_EXPORT_METHOD(getCurrentPosition:(NSDictionary *)optionsJSON
   }
 
   // Check if previous recorded location exists and is good enough
-  RCTLocationOptions options = [RCTConvert RCTLocationOptions:optionsJSON];
   if (_lastLocationEvent &&
       CFAbsoluteTimeGetCurrent() - [RCTConvert NSTimeInterval:_lastLocationEvent[@"timestamp"]] < options.maximumAge &&
       [_lastLocationEvent[@"coords"][@"accuracy"] doubleValue] >= options.accuracy) {
diff --git a/React/Base/RCTBridge.m b/React/Base/RCTBridge.m
index 67c86fb12..7dc2322f0 100644
--- a/React/Base/RCTBridge.m
+++ b/React/Base/RCTBridge.m
@@ -355,7 +355,7 @@ static NSString *RCTStringUpToFirstArgument(NSString *methodName)
 
 #define RCT_CONVERT_CASE(_value, _type) \
   case _value: { \
-    _type (*convert)(id, SEL, id) = (typeof(convert))[RCTConvert methodForSelector:selector]; \
+    _type (*convert)(id, SEL, id) = (typeof(convert))objc_msgSend; \
     RCT_ARG_BLOCK( _type value = convert([RCTConvert class], selector, json); ) \
     break; \
   }
@@ -377,12 +377,27 @@ static NSString *RCTStringUpToFirstArgument(NSString *methodName)
               RCT_CONVERT_CASE('B', BOOL)
               RCT_CONVERT_CASE('@', id)
               RCT_CONVERT_CASE('^', void *)
-            case '{':
-              RCTAssert(NO, @"Argument %zd of %C[%@ %@] is defined as %@, however RCT_EXPORT_METHOD() "
-                        "does not currently support struct-type arguments.", i - 2,
-                        [reactMethodName characterAtIndex:0], _moduleClassName,
-                        objCMethodName, argumentName);
-              break;
+
+              case '{': {
+                [argumentBlocks addObject:^(RCTBridge *bridge, NSNumber *context, NSInvocation *invocation, NSUInteger index, id json) {
+                  NSUInteger size;
+                  NSGetSizeAndAlignment(argumentType, &size, NULL);
+                  void *returnValue = malloc(size);
+                  NSMethodSignature *methodSignature = [RCTConvert methodSignatureForSelector:selector];
+                  NSInvocation *_invocation = [NSInvocation invocationWithMethodSignature:methodSignature];
+                  [_invocation setTarget:[RCTConvert class]];
+                  [_invocation setSelector:selector];
+                  [_invocation setArgument:&json atIndex:2];
+                  [_invocation invoke];
+                  [_invocation getReturnValue:returnValue];
+
+                  [invocation setArgument:returnValue atIndex:index];
+
+                  free(returnValue);
+                }];
+                break;
+              }
+
             default:
               defaultCase(argumentType);
           }
@@ -438,6 +453,10 @@ static NSString *RCTStringUpToFirstArgument(NSString *methodName)
             RCT_SIMPLE_CASE('d', double, doubleValue)
             RCT_SIMPLE_CASE('B', BOOL, boolValue)
 
+          case '{':
+            RCTLogMustFix(@"Cannot convert JSON to struct %s", argumentType);
+            break;
+
           default:
             defaultCase(argumentType);
         }
diff --git a/React/Modules/RCTUIManager.m b/React/Modules/RCTUIManager.m
index 451a343d0..b7ae182ba 100644
--- a/React/Modules/RCTUIManager.m
+++ b/React/Modules/RCTUIManager.m
@@ -1001,12 +1001,11 @@ RCT_EXPORT_METHOD(measureLayoutRelativeToParent:(NSNumber *)reactTag
  * Only layouts for views that are within the rect passed in are returned. Invokes the error callback if the
  * passed in parent view does not exist. Invokes the supplied callback with the array of computed layouts.
  */
-RCT_EXPORT_METHOD(measureViewsInRect:(id)rectJSON
+RCT_EXPORT_METHOD(measureViewsInRect:(CGRect)rect
                   parentView:(NSNumber *)reactTag
                   errorCallback:(RCTResponseSenderBlock)errorCallback
                   callback:(RCTResponseSenderBlock)callback)
 {
-  CGRect rect = [RCTConvert CGRect:rectJSON];
   RCTShadowView *shadowView = _shadowViewRegistry[reactTag];
   if (!shadowView) {
     RCTLogError(@"Attempting to measure view that does not exist (tag #%@)", reactTag);
@@ -1102,9 +1101,8 @@ RCT_EXPORT_METHOD(scrollWithoutAnimationTo:(NSNumber *)reactTag
 }
 
 RCT_EXPORT_METHOD(zoomToRect:(NSNumber *)reactTag
-                  withRect:(id)rectJSON)
+                  withRect:(CGRect)rect)
 {
-  CGRect rect = [RCTConvert CGRect:rectJSON];
   [self addUIBlock:^(RCTUIManager *uiManager, RCTSparseArray *viewRegistry){
     UIView *view = viewRegistry[reactTag];
     if ([view conformsToProtocol:@protocol(RCTScrollableProtocol)]) {