diff --git a/patches/patchinstall.sh b/patches/patchinstall.sh
index 48a2b148..34c385fd 100755
--- a/patches/patchinstall.sh
+++ b/patches/patchinstall.sh
@@ -483,6 +483,7 @@ patch_enable_all ()
 	enable_ws2_32_Tests="$1"
 	enable_ws2_32_TransmitFile="$1"
 	enable_ws2_32_WSACleanup="$1"
+	enable_ws2_32_WSAIoctl="$1"
 	enable_ws2_32_WriteWatches="$1"
 	enable_ws2_32_getsockopt="$1"
 	enable_wtsapi32_EnumerateProcesses="$1"
@@ -1700,6 +1701,9 @@ patch_enable ()
 		ws2_32-WSACleanup)
 			enable_ws2_32_WSACleanup="$2"
 			;;
+		ws2_32-WSAIoctl)
+			enable_ws2_32_WSAIoctl="$2"
+			;;
 		ws2_32-WriteWatches)
 			enable_ws2_32_WriteWatches="$2"
 			;;
@@ -9853,6 +9857,21 @@ if test "$enable_ws2_32_WSACleanup" -eq 1; then
 	) >> "$patchlist"
 fi
 
+# Patchset ws2_32-WSAIoctl
+# |
+# | This patchset fixes the following Wine bugs:
+# |   *	[#43315] Set return size when calling WSAIoctl with WS_SIO_GET_EXTENSION_FUNCTION_POINTER
+# |
+# | Modified files:
+# |   *	dlls/ws2_32/socket.c, dlls/ws2_32/tests/sock.c
+# |
+if test "$enable_ws2_32_WSAIoctl" -eq 1; then
+	patch_apply ws2_32-WSAIoctl/0001-ws2_32-Set-return-size-when-calling-WSAIoctl-with-WS.patch
+	(
+		printf '%s\n' '+    { "Kimmo Myllyvirta", "ws2_32: Set return size when calling WSAIoctl with WS_SIO_GET_EXTENSION_FUNCTION_POINTER.", 1 },';
+	) >> "$patchlist"
+fi
+
 # Patchset ws2_32-getsockopt
 # |
 # | This patchset fixes the following Wine bugs:
diff --git a/patches/ws2_32-WSAIoctl/0001-ws2_32-Set-return-size-when-calling-WSAIoctl-with-WS.patch b/patches/ws2_32-WSAIoctl/0001-ws2_32-Set-return-size-when-calling-WSAIoctl-with-WS.patch
new file mode 100644
index 00000000..95372532
--- /dev/null
+++ b/patches/ws2_32-WSAIoctl/0001-ws2_32-Set-return-size-when-calling-WSAIoctl-with-WS.patch
@@ -0,0 +1,47 @@
+From bc57f2c994179bbb3d0e8e2048b7b6011a84e3ab Mon Sep 17 00:00:00 2001
+From: Kimmo Myllyvirta <kimmo.myllyvirta@gmail.com>
+Date: Tue, 11 Jul 2017 11:42:06 +0200
+Subject: ws2_32: Set return size when calling WSAIoctl with
+ WS_SIO_GET_EXTENSION_FUNCTION_POINTER.
+
+---
+ dlls/ws2_32/socket.c     | 1 +
+ dlls/ws2_32/tests/sock.c | 3 +++
+ 2 files changed, 4 insertions(+)
+
+diff --git a/dlls/ws2_32/socket.c b/dlls/ws2_32/socket.c
+index 48d8f61553d..fac47d78527 100644
+--- a/dlls/ws2_32/socket.c
++++ b/dlls/ws2_32/socket.c
+@@ -4985,6 +4985,7 @@ INT WINAPI WSAIoctl(SOCKET s, DWORD code, LPVOID in_buff, DWORD in_size, LPVOID
+         {
+             TRACE("-> got %s\n", guid_funcs[i].name);
+             *(void **)out_buff = guid_funcs[i].func_ptr;
++            total = sizeof(void *);
+             break;
+         }
+ 
+diff --git a/dlls/ws2_32/tests/sock.c b/dlls/ws2_32/tests/sock.c
+index c66d0d9ccd9..91f2525c174 100644
+--- a/dlls/ws2_32/tests/sock.c
++++ b/dlls/ws2_32/tests/sock.c
+@@ -7704,6 +7704,7 @@ static void test_ConnectEx(void)
+         goto end;
+     }
+ 
++    bytesReturned = 0xdeadbeef;
+     iret = WSAIoctl(connector, SIO_GET_EXTENSION_FUNCTION_POINTER, &connectExGuid, sizeof(connectExGuid),
+         &pConnectEx, sizeof(pConnectEx), &bytesReturned, NULL, NULL);
+     if (iret) {
+@@ -7711,6 +7712,8 @@ static void test_ConnectEx(void)
+         goto end;
+     }
+ 
++    ok(bytesReturned == sizeof(pConnectEx), "expected sizeof(pConnectEx), got %u\n", bytesReturned);
++
+     bret = pConnectEx(INVALID_SOCKET, (struct sockaddr*)&address, addrlen, NULL, 0, &bytesReturned, &overlapped);
+     ok(bret == FALSE && WSAGetLastError() == WSAENOTSOCK, "ConnectEx on invalid socket "
+         "returned %d + errno %d\n", bret, WSAGetLastError());
+-- 
+2.13.1
+
diff --git a/patches/ws2_32-WSAIoctl/definition b/patches/ws2_32-WSAIoctl/definition
new file mode 100644
index 00000000..62ea77e6
--- /dev/null
+++ b/patches/ws2_32-WSAIoctl/definition
@@ -0,0 +1 @@
+Fixes: [43315] Set return size when calling WSAIoctl with WS_SIO_GET_EXTENSION_FUNCTION_POINTER