diff --git a/Libraries/WebSocket/RCTSRWebSocket.h b/Libraries/WebSocket/RCTSRWebSocket.h
index 1b17cffaf47c08..4784ec92c56a79 100644
--- a/Libraries/WebSocket/RCTSRWebSocket.h
+++ b/Libraries/WebSocket/RCTSRWebSocket.h
@@ -80,6 +80,8 @@ extern NSString *const RCTSRHTTPResponseErrorKey;
 - (void)open;
 
 - (void)close;
+- (void)closeSync;
+
 - (void)closeWithCode:(NSInteger)code reason:(NSString *)reason;
 
 // Send a UTF8 String or Data.
diff --git a/Libraries/WebSocket/RCTSRWebSocket.m b/Libraries/WebSocket/RCTSRWebSocket.m
index 8ce6edc4dae216..a843ca6e4e7c76 100644
--- a/Libraries/WebSocket/RCTSRWebSocket.m
+++ b/Libraries/WebSocket/RCTSRWebSocket.m
@@ -554,48 +554,65 @@ - (void)close
   [self closeWithCode:RCTSRStatusCodeNormal reason:nil];
 }
 
+- (void)closeSync
+{
+  [self closeWithCode:RCTSRStatusCodeNormal reason:nil isBlocking:YES];
+}
+
 - (void)closeWithCode:(NSInteger)code reason:(NSString *)reason
 {
-  assert(code);
-  dispatch_async(_workQueue, ^{
-    if (self.readyState == RCTSR_CLOSING || self.readyState == RCTSR_CLOSED) {
-      return;
-    }
+  [self closeWithCode:code reason:reason isBlocking:NO];
+}
 
-    BOOL wasConnecting = self.readyState == RCTSR_CONNECTING;
+- (void)closeWithCode:(NSInteger)code reason:(NSString *)reason isBlocking:(BOOL)isBlocking
+{
+    assert(code);
+  
+    void (^performClose)(void) = ^{
+      if (self.readyState == RCTSR_CLOSING || self.readyState == RCTSR_CLOSED) {
+        return;
+      }
 
-    self.readyState = RCTSR_CLOSING;
+      BOOL wasConnecting = self.readyState == RCTSR_CONNECTING;
 
-    RCTSRLog(@"Closing with code %ld reason %@", code, reason);
+      self.readyState = RCTSR_CLOSING;
 
-    if (wasConnecting) {
-      [self _disconnect];
-      return;
-    }
+      RCTSRLog(@"Closing with code %ld reason %@", code, reason);
+
+      if (wasConnecting) {
+        [self _disconnect:isBlocking];
+        return;
+      }
 
-    size_t maxMsgSize = [reason maximumLengthOfBytesUsingEncoding:NSUTF8StringEncoding];
-    NSMutableData *mutablePayload = [[NSMutableData alloc] initWithLength:sizeof(uint16_t) + maxMsgSize];
-    NSData *payload = mutablePayload;
+      size_t maxMsgSize = [reason maximumLengthOfBytesUsingEncoding:NSUTF8StringEncoding];
+      NSMutableData *mutablePayload = [[NSMutableData alloc] initWithLength:sizeof(uint16_t) + maxMsgSize];
+      NSData *payload = mutablePayload;
 
-    ((uint16_t *)mutablePayload.mutableBytes)[0] = NSSwapBigShortToHost(code);
+      ((uint16_t *)mutablePayload.mutableBytes)[0] = NSSwapBigShortToHost(code);
 
-    if (reason) {
-      NSRange remainingRange = {0};
+      if (reason) {
+        NSRange remainingRange = {0};
 
-      NSUInteger usedLength = 0;
+        NSUInteger usedLength = 0;
 
-      BOOL success __unused = [reason getBytes:(char *)mutablePayload.mutableBytes + sizeof(uint16_t) maxLength:payload.length - sizeof(uint16_t) usedLength:&usedLength encoding:NSUTF8StringEncoding options:NSStringEncodingConversionExternalRepresentation range:NSMakeRange(0, reason.length) remainingRange:&remainingRange];
+        BOOL success __unused = [reason getBytes:(char *)mutablePayload.mutableBytes + sizeof(uint16_t) maxLength:payload.length - sizeof(uint16_t) usedLength:&usedLength encoding:NSUTF8StringEncoding options:NSStringEncodingConversionExternalRepresentation range:NSMakeRange(0, reason.length) remainingRange:&remainingRange];
 
-      assert(success);
-      assert(remainingRange.length == 0);
+        assert(success);
+        assert(remainingRange.length == 0);
 
-      if (usedLength != maxMsgSize) {
-        payload = [payload subdataWithRange:NSMakeRange(0, usedLength + sizeof(uint16_t))];
+        if (usedLength != maxMsgSize) {
+          payload = [payload subdataWithRange:NSMakeRange(0, usedLength + sizeof(uint16_t))];
+        }
       }
-    }
 
-    [self _sendFrameWithOpcode:RCTSROpCodeConnectionClose data:payload];
-  });
+      [self _sendFrameWithOpcode:RCTSROpCodeConnectionClose data:payload skipWorkQueueAssertion:isBlocking];
+    };
+    
+    if (isBlocking) {
+      performClose();
+    } else {
+      dispatch_async(_workQueue, performClose);
+    }
 }
 
 - (void)_closeWithProtocolError:(NSString *)message
@@ -630,15 +647,22 @@ - (void)_failWithError:(NSError *)error
   });
 }
 
-- (void)_writeData:(NSData *)data
+- (void)_writeData:(NSData *)data skipWorkQueueAssertion:(BOOL)skipWorkQueueAssertion
 {
-  [self assertOnWorkQueue];
+  if (skipWorkQueueAssertion == NO){
+    [self assertOnWorkQueue];
+  }
 
   if (_closeWhenFinishedWriting) {
     return;
   }
   [_outputBuffer appendData:data];
-  [self _pumpWriting];
+  [self _pumpWriting:skipWorkQueueAssertion];
+}
+
+- (void)_writeData:(NSData *)data
+{
+  [self _writeData:data skipWorkQueueAssertion:NO];
 }
 
 - (void)send:(id)data
@@ -772,14 +796,22 @@ - (void)handleCloseWithData:(NSData *)data
   });
 }
 
-- (void)_disconnect
+- (void)_disconnect:(BOOL)skipWorkQueueAssertion
 {
-  [self assertOnWorkQueue];
+  if (skipWorkQueueAssertion == NO) {
+    [self assertOnWorkQueue];
+  }
+
   RCTSRLog(@"Trying to disconnect");
   _closeWhenFinishedWriting = YES;
   [self _pumpWriting];
 }
 
+- (void)_disconnect
+{
+  [self _disconnect:NO];
+}
+
 - (void)_handleFrameWithData:(NSData *)frameData opCode:(NSInteger)opcode
 {
   // Check that the current data is valid UTF8
@@ -1005,9 +1037,14 @@ - (void)_readFrameNew
   });
 }
 
-- (void)_pumpWriting
+- (void)_pumpWriting {
+  [self _pumpWriting:NO];
+}
+- (void)_pumpWriting:(BOOL)skipWorkQueueAssertion
 {
-  [self assertOnWorkQueue];
+    if (skipWorkQueueAssertion == NO) {
+        [self assertOnWorkQueue];
+    }
 
   NSUInteger dataLength = _outputBuffer.length;
   if (dataLength - _outputBufferOffset > 0 && _outputStream.hasSpaceAvailable) {
@@ -1223,9 +1260,16 @@ - (void)_pumpScanner
 
 static const size_t RCTSRFrameHeaderOverhead = 32;
 
-- (void)_sendFrameWithOpcode:(RCTSROpCode)opcode data:(NSData *)data
+- (void)_sendFrameWithOpcode:(RCTSROpCode)opcode data:(NSData *)data {
+  [self _sendFrameWithOpcode:opcode data:data skipWorkQueueAssertion:NO];
+}
+
+
+- (void)_sendFrameWithOpcode:(RCTSROpCode)opcode data:(NSData *)data skipWorkQueueAssertion:(BOOL)skipWorkQueueAssertion
 {
-  [self assertOnWorkQueue];
+  if (skipWorkQueueAssertion == NO) {
+    [self assertOnWorkQueue];
+  }
 
   if (nil == data) {
     return;
@@ -1290,7 +1334,7 @@ - (void)_sendFrameWithOpcode:(RCTSROpCode)opcode data:(NSData *)data
   assert(frame_buffer_size <= [frame length]);
   frame.length = frame_buffer_size;
 
-  [self _writeData:frame];
+  [self _writeData:frame skipWorkQueueAssertion:skipWorkQueueAssertion];
 }
 
 - (void)stream:(NSStream *)aStream handleEvent:(NSStreamEvent)eventCode
diff --git a/React/CoreModules/RCTWebSocketModule.h b/React/CoreModules/RCTWebSocketModule.h
index c1a48d3d31b9a3..b658c7197cc018 100644
--- a/React/CoreModules/RCTWebSocketModule.h
+++ b/React/CoreModules/RCTWebSocketModule.h
@@ -24,6 +24,9 @@ NS_ASSUME_NONNULL_BEGIN
 
 - (void)sendData:(NSData *)data forSocketID:(nonnull NSNumber *)socketID;
 
+// Closes all open websockets on the main thread
+- (void)flush;
+
 @end
 
 @interface RCTBridge (RCTWebSocketModule)
diff --git a/React/CoreModules/RCTWebSocketModule.mm b/React/CoreModules/RCTWebSocketModule.mm
index 32889ea7d4bddb..48fe67e01e0bef 100644
--- a/React/CoreModules/RCTWebSocketModule.mm
+++ b/React/CoreModules/RCTWebSocketModule.mm
@@ -51,6 +51,16 @@ - (NSArray *)supportedEvents
   return @[ @"websocketMessage", @"websocketOpen", @"websocketFailed", @"websocketClosed" ];
 }
 
+
+- (void)flush
+{
+  _contentHandlers = nil;
+  for (RCTSRWebSocket *socket in _sockets.allValues) {
+    socket.delegate = nil;
+    [socket closeSync];
+  }
+}
+
 - (void)invalidate
 {
   [super invalidate];