diff --git a/Libraries/ART/RCTConvert+ART.m b/Libraries/ART/RCTConvert+ART.m
index 704f12697..6135dc4f4 100644
--- a/Libraries/ART/RCTConvert+ART.m
+++ b/Libraries/ART/RCTConvert+ART.m
@@ -51,7 +51,7 @@
           CGPathAddArc(path, NULL, NEXT_VALUE, NEXT_VALUE, NEXT_VALUE, NEXT_VALUE, NEXT_VALUE, NEXT_VALUE == 0);
           break;
         default:
-          RCTLogError(@"Invalid CGPath type %zd at element %zd of %@", type, i, arr);
+          RCTLogError(@"Invalid CGPath type %llu at element %llu of %@", (unsigned long long)type, (unsigned long long)i, arr);
           CGPathRelease(path);
           return NULL;
       }
@@ -158,7 +158,7 @@ RCT_ENUM_CONVERTER(CTTextAlignment, (@{
     case 3: // pattern
       return [[ARTPattern alloc] initWithArray:arr];
     default:
-      RCTLogError(@"Unknown brush type: %zd", type);
+      RCTLogError(@"Unknown brush type: %llu", (unsigned long long)type);
       return nil;
   }
 }
@@ -167,7 +167,7 @@ RCT_ENUM_CONVERTER(CTTextAlignment, (@{
 {
   NSArray *arr = [self NSArray:json];
   if (arr.count < offset + 2) {
-    RCTLogError(@"Too few elements in array (expected at least %zd): %@", 2 + offset, arr);
+    RCTLogError(@"Too few elements in array (expected at least %llu): %@", (unsigned long long)(2 + offset), arr);
     return CGPointZero;
   }
   return (CGPoint){
@@ -180,7 +180,7 @@ RCT_ENUM_CONVERTER(CTTextAlignment, (@{
 {
   NSArray *arr = [self NSArray:json];
   if (arr.count < offset + 4) {
-    RCTLogError(@"Too few elements in array (expected at least %zd): %@", 4 + offset, arr);
+    RCTLogError(@"Too few elements in array (expected at least %llu): %@", (unsigned long long)(4 + offset), arr);
     return CGRectZero;
   }
   return (CGRect){
@@ -193,7 +193,7 @@ RCT_ENUM_CONVERTER(CTTextAlignment, (@{
 {
   NSArray *arr = [self NSArray:json];
   if (arr.count < offset + 4) {
-    RCTLogError(@"Too few elements in array (expected at least %zd): %@", 4 + offset, arr);
+    RCTLogError(@"Too few elements in array (expected at least %llu): %@", (unsigned long long)(4 + offset), arr);
     return NULL;
   }
   return [self CGColor:[arr subarrayWithRange:(NSRange){offset, 4}]];
@@ -203,7 +203,7 @@ RCT_ENUM_CONVERTER(CTTextAlignment, (@{
 {
   NSArray *arr = [self NSArray:json];
   if (arr.count < offset) {
-    RCTLogError(@"Too few elements in array (expected at least %zd): %@", offset, arr);
+    RCTLogError(@"Too few elements in array (expected at least %llu): %@", (unsigned long long)offset, arr);
     return NULL;
   }
   arr = [arr subarrayWithRange:(NSRange){offset, arr.count - offset}];
diff --git a/Libraries/Text/RCTTextField.m b/Libraries/Text/RCTTextField.m
index fa548c480..567ab31a9 100644
--- a/Libraries/Text/RCTTextField.m
+++ b/Libraries/Text/RCTTextField.m
@@ -90,7 +90,7 @@ RCT_NOT_IMPLEMENTED(- (instancetype)initWithCoder:(NSCoder *)aDecoder)
                               notifyDelegate:YES];
     }
   } else if (eventLag > RCTTextUpdateLagWarningThreshold) {
-    RCTLogWarn(@"Native TextInput(%@) is %zd events ahead of JS - try to make your JS faster.", _backedTextInput.text, eventLag);
+    RCTLogWarn(@"Native TextInput(%@) is %lld events ahead of JS - try to make your JS faster.", _backedTextInput.text, (long long)eventLag);
   }
 }
 
diff --git a/Libraries/Text/RCTTextInput.m b/Libraries/Text/RCTTextInput.m
index 4c63c2ef4..ed7bade62 100644
--- a/Libraries/Text/RCTTextInput.m
+++ b/Libraries/Text/RCTTextInput.m
@@ -87,7 +87,7 @@ RCT_NOT_IMPLEMENTED(- (instancetype)initWithFrame:(CGRect)frame)
   if (eventLag == 0 && ![previousSelectedTextRange isEqual:selectedTextRange]) {
     [backedTextInput setSelectedTextRange:selectedTextRange notifyDelegate:NO];
   } else if (eventLag > RCTTextUpdateLagWarningThreshold) {
-    RCTLogWarn(@"Native TextInput(%@) is %zd events ahead of JS - try to make your JS faster.", backedTextInput.text, eventLag);
+    RCTLogWarn(@"Native TextInput(%@) is %lld events ahead of JS - try to make your JS faster.", backedTextInput.text, (long long)eventLag);
   }
 }
 
diff --git a/Libraries/Text/RCTTextView.m b/Libraries/Text/RCTTextView.m
index 310691db4..3342e445e 100644
--- a/Libraries/Text/RCTTextView.m
+++ b/Libraries/Text/RCTTextView.m
@@ -235,7 +235,7 @@ static NSAttributedString *removeReactTagFromString(NSAttributedString *string)
 
     [self invalidateContentSize];
   } else if (eventLag > RCTTextUpdateLagWarningThreshold) {
-    RCTLogWarn(@"Native TextInput(%@) is %zd events ahead of JS - try to make your JS faster.", self.text, eventLag);
+    RCTLogWarn(@"Native TextInput(%@) is %lld events ahead of JS - try to make your JS faster.", self.text, (long long)eventLag);
   }
 }
 
diff --git a/Libraries/WebSocket/RCTWebSocketExecutor.m b/Libraries/WebSocket/RCTWebSocketExecutor.m
index ecb0b260c..520337178 100644
--- a/Libraries/WebSocket/RCTWebSocketExecutor.m
+++ b/Libraries/WebSocket/RCTWebSocketExecutor.m
@@ -56,7 +56,7 @@ RCT_EXPORT_MODULE()
   if (!_url) {
     NSInteger port = [[[_bridge bundleURL] port] integerValue] ?: 8081;
     NSString *host = [[_bridge bundleURL] host] ?: @"localhost";
-    NSString *URLString = [NSString stringWithFormat:@"http://%@:%zd/debugger-proxy?role=client", host, port];
+    NSString *URLString = [NSString stringWithFormat:@"http://%@:%lld/debugger-proxy?role=client", host, (long long)port];
     _url = [RCTConvert NSURL:URLString];
   }
 
diff --git a/React/Base/RCTConvert.m b/React/Base/RCTConvert.m
index f7d054adc..759c577c7 100644
--- a/React/Base/RCTConvert.m
+++ b/React/Base/RCTConvert.m
@@ -68,7 +68,7 @@ RCT_CUSTOM_CONVERTER(NSData *, NSData, [json dataUsingEncoding:NSUTF8StringEncod
   for (NSNumber *number in json) {
     NSInteger index = number.integerValue;
     if (RCT_DEBUG && index < 0) {
-      RCTLogError(@"Invalid index value %zd. Indices must be positive.", index);
+      RCTLogError(@"Invalid index value %lld. Indices must be positive.", (long long)index);
     }
     [indexSet addIndex:index];
   }
@@ -403,7 +403,7 @@ static void convertCGStruct(const char *type, NSArray *fields, CGFloat *result,
   NSUInteger count = fields.count;
   if ([json isKindOfClass:[NSArray class]]) {
     if (RCT_DEBUG && [json count] != count) {
-      RCTLogError(@"Expected array with count %zd, but count is %zd: %@", count, [json count], json);
+      RCTLogError(@"Expected array with count %llu, but count is %llu: %@", (unsigned long long)count, (unsigned long long)[json count], json);
     } else {
       for (NSUInteger i = 0; i < count; i++) {
         result[i] = [RCTConvert CGFloat:RCTNilIfNull(json[i])];
diff --git a/React/Base/RCTKeyCommands.m b/React/Base/RCTKeyCommands.m
index 93c21d08f..29ceb84f9 100644
--- a/React/Base/RCTKeyCommands.m
+++ b/React/Base/RCTKeyCommands.m
@@ -68,8 +68,8 @@ RCT_NOT_IMPLEMENTED(- (instancetype)init)
 
 - (NSString *)description
 {
-  return [NSString stringWithFormat:@"<%@:%p input=\"%@\" flags=%zd hasBlock=%@>",
-          [self class], self, _keyCommand.input, _keyCommand.modifierFlags,
+  return [NSString stringWithFormat:@"<%@:%p input=\"%@\" flags=%lld hasBlock=%@>",
+          [self class], self, _keyCommand.input, (long long)_keyCommand.modifierFlags,
           _block ? @"YES" : @"NO"];
 }
 
diff --git a/React/Base/RCTModuleMethod.mm b/React/Base/RCTModuleMethod.mm
index 15ddf7065..c26ef1c28 100644
--- a/React/Base/RCTModuleMethod.mm
+++ b/React/Base/RCTModuleMethod.mm
@@ -493,12 +493,12 @@ RCT_EXTERN_C_END
       expectedCount -= 2;
     }
 
-    RCTLogError(@"%@.%s was called with %zd arguments but expects %zd arguments. "
+    RCTLogError(@"%@.%s was called with %lld arguments but expects %lld arguments. "
                 @"If you haven\'t changed this method yourself, this usually means that "
                 @"your versions of the native code and JavaScript code are out of sync. "
                 @"Updating both should make this error go away.",
                 RCTBridgeModuleNameForClass(_moduleClass), self.JSMethodName,
-                actualCount, expectedCount);
+                (long long)actualCount, (long long)expectedCount);
     return nil;
   }
 #endif
diff --git a/React/Modules/RCTLayoutAnimation.m b/React/Modules/RCTLayoutAnimation.m
index 3d3bf3b5c..4d5bf29c4 100644
--- a/React/Modules/RCTLayoutAnimation.m
+++ b/React/Modules/RCTLayoutAnimation.m
@@ -30,7 +30,7 @@ static UIViewAnimationOptions UIViewAnimationOptionsFromRCTAnimationType(RCTAnim
       // http://stackoverflow.com/questions/18870447/how-to-use-the-default-ios7-uianimation-curve
       return (UIViewAnimationOptions)(_currentKeyboardAnimationCurve << 16);
     default:
-      RCTLogError(@"Unsupported animation type %zd", type);
+      RCTLogError(@"Unsupported animation type %lld", (long long)type);
       return UIViewAnimationOptionCurveEaseInOut;
   }
 }
diff --git a/React/Modules/RCTRedBox.m b/React/Modules/RCTRedBox.m
index dbcea6513..7eeb19bb0 100644
--- a/React/Modules/RCTRedBox.m
+++ b/React/Modules/RCTRedBox.m
@@ -186,12 +186,12 @@ RCT_NOT_IMPLEMENTED(- (instancetype)initWithCoder:(NSCoder *)aDecoder)
 - (NSString *)formatFrameSource:(RCTJSStackFrame *)stackFrame
 {
   NSString *fileName = RCTNilIfNull(stackFrame.file) ? [stackFrame.file lastPathComponent] : @"<unknown file>";
-  NSString *lineInfo = [NSString stringWithFormat:@"%@:%zd",
+  NSString *lineInfo = [NSString stringWithFormat:@"%@:%lld",
                         fileName,
-                        stackFrame.lineNumber];
+                        (long long)stackFrame.lineNumber];
 
   if (stackFrame.column != 0) {
-    lineInfo = [lineInfo stringByAppendingFormat:@":%zd", stackFrame.column];
+    lineInfo = [lineInfo stringByAppendingFormat:@":%lld", (long long)stackFrame.column];
   }
   return lineInfo;
 }
diff --git a/React/Views/RCTView.m b/React/Views/RCTView.m
index c434a0290..dfa5f4534 100644
--- a/React/Views/RCTView.m
+++ b/React/Views/RCTView.m
@@ -197,7 +197,7 @@ RCT_NOT_IMPLEMENTED(- (instancetype)initWithCoder:unused)
     case RCTPointerEventsBoxNone:
       return hitSubview;
     default:
-      RCTLogError(@"Invalid pointer-events specified %zd on %@", _pointerEvents, self);
+      RCTLogError(@"Invalid pointer-events specified %lld on %@", (long long)_pointerEvents, self);
       return hitSubview ?: hitView;
   }
 }
diff --git a/React/Views/RCTWebViewManager.m b/React/Views/RCTWebViewManager.m
index ddc66e2b8..ec6192ef5 100644
--- a/React/Views/RCTWebViewManager.m
+++ b/React/Views/RCTWebViewManager.m
@@ -153,7 +153,7 @@ RCT_EXPORT_METHOD(startLoadWithResult:(BOOL)result lockIdentifier:(NSInteger)loc
     [_shouldStartLoadLock unlockWithCondition:0];
   } else {
     RCTLogWarn(@"startLoadWithResult invoked with invalid lockIdentifier: "
-               "got %zd, expected %zd", lockIdentifier, _shouldStartLoadLock.condition);
+               "got %lld, expected %lld", (long long)lockIdentifier, (long long)_shouldStartLoadLock.condition);
   }
 }