diff --git a/lsteamclient/cppISteamClient_SteamClient007.cpp b/lsteamclient/cppISteamClient_SteamClient007.cpp
index ced40905..846b4967 100644
--- a/lsteamclient/cppISteamClient_SteamClient007.cpp
+++ b/lsteamclient/cppISteamClient_SteamClient007.cpp
@@ -112,6 +112,7 @@ void *cppISteamClient_SteamClient007_GetISteamNetworking(void *linux_side, HStea
 
 void cppISteamClient_SteamClient007_SetWarningMessageHook(void *linux_side, SteamAPIWarningMessageHook_t pFunction)
 {
+    pFunction = (SteamAPIWarningMessageHook_t)manual_convert_SteamAPIWarningMessageHook_t((void*)pFunction);
     ((ISteamClient*)linux_side)->SetWarningMessageHook((SteamAPIWarningMessageHook_t)pFunction);
 }
 
diff --git a/lsteamclient/cppISteamClient_SteamClient008.cpp b/lsteamclient/cppISteamClient_SteamClient008.cpp
index 499d8056..8c24b7fb 100644
--- a/lsteamclient/cppISteamClient_SteamClient008.cpp
+++ b/lsteamclient/cppISteamClient_SteamClient008.cpp
@@ -112,6 +112,7 @@ uint32 cppISteamClient_SteamClient008_GetIPCCallCount(void *linux_side)
 
 void cppISteamClient_SteamClient008_SetWarningMessageHook(void *linux_side, SteamAPIWarningMessageHook_t pFunction)
 {
+    pFunction = (SteamAPIWarningMessageHook_t)manual_convert_SteamAPIWarningMessageHook_t((void*)pFunction);
     ((ISteamClient*)linux_side)->SetWarningMessageHook((SteamAPIWarningMessageHook_t)pFunction);
 }
 
diff --git a/lsteamclient/cppISteamClient_SteamClient009.cpp b/lsteamclient/cppISteamClient_SteamClient009.cpp
index d399f605..1fa46c04 100644
--- a/lsteamclient/cppISteamClient_SteamClient009.cpp
+++ b/lsteamclient/cppISteamClient_SteamClient009.cpp
@@ -117,6 +117,7 @@ uint32 cppISteamClient_SteamClient009_GetIPCCallCount(void *linux_side)
 
 void cppISteamClient_SteamClient009_SetWarningMessageHook(void *linux_side, SteamAPIWarningMessageHook_t pFunction)
 {
+    pFunction = (SteamAPIWarningMessageHook_t)manual_convert_SteamAPIWarningMessageHook_t((void*)pFunction);
     ((ISteamClient*)linux_side)->SetWarningMessageHook((SteamAPIWarningMessageHook_t)pFunction);
 }
 
diff --git a/lsteamclient/cppISteamClient_SteamClient010.cpp b/lsteamclient/cppISteamClient_SteamClient010.cpp
index 61969703..ff611afa 100644
--- a/lsteamclient/cppISteamClient_SteamClient010.cpp
+++ b/lsteamclient/cppISteamClient_SteamClient010.cpp
@@ -117,6 +117,7 @@ uint32 cppISteamClient_SteamClient010_GetIPCCallCount(void *linux_side)
 
 void cppISteamClient_SteamClient010_SetWarningMessageHook(void *linux_side, SteamAPIWarningMessageHook_t pFunction)
 {
+    pFunction = (SteamAPIWarningMessageHook_t)manual_convert_SteamAPIWarningMessageHook_t((void*)pFunction);
     ((ISteamClient*)linux_side)->SetWarningMessageHook((SteamAPIWarningMessageHook_t)pFunction);
 }
 
diff --git a/lsteamclient/cppISteamClient_SteamClient011.cpp b/lsteamclient/cppISteamClient_SteamClient011.cpp
index d9f513f2..1cc25eda 100644
--- a/lsteamclient/cppISteamClient_SteamClient011.cpp
+++ b/lsteamclient/cppISteamClient_SteamClient011.cpp
@@ -122,6 +122,7 @@ uint32 cppISteamClient_SteamClient011_GetIPCCallCount(void *linux_side)
 
 void cppISteamClient_SteamClient011_SetWarningMessageHook(void *linux_side, SteamAPIWarningMessageHook_t pFunction)
 {
+    pFunction = (SteamAPIWarningMessageHook_t)manual_convert_SteamAPIWarningMessageHook_t((void*)pFunction);
     ((ISteamClient*)linux_side)->SetWarningMessageHook((SteamAPIWarningMessageHook_t)pFunction);
 }
 
diff --git a/lsteamclient/cppISteamClient_SteamClient012.cpp b/lsteamclient/cppISteamClient_SteamClient012.cpp
index 5bd294e8..422dfb59 100644
--- a/lsteamclient/cppISteamClient_SteamClient012.cpp
+++ b/lsteamclient/cppISteamClient_SteamClient012.cpp
@@ -117,6 +117,7 @@ uint32 cppISteamClient_SteamClient012_GetIPCCallCount(void *linux_side)
 
 void cppISteamClient_SteamClient012_SetWarningMessageHook(void *linux_side, SteamAPIWarningMessageHook_t pFunction)
 {
+    pFunction = (SteamAPIWarningMessageHook_t)manual_convert_SteamAPIWarningMessageHook_t((void*)pFunction);
     ((ISteamClient*)linux_side)->SetWarningMessageHook((SteamAPIWarningMessageHook_t)pFunction);
 }
 
diff --git a/lsteamclient/cppISteamClient_SteamClient013.cpp b/lsteamclient/cppISteamClient_SteamClient013.cpp
index fe84eb68..401d93df 100644
--- a/lsteamclient/cppISteamClient_SteamClient013.cpp
+++ b/lsteamclient/cppISteamClient_SteamClient013.cpp
@@ -117,6 +117,7 @@ uint32 cppISteamClient_SteamClient013_GetIPCCallCount(void *linux_side)
 
 void cppISteamClient_SteamClient013_SetWarningMessageHook(void *linux_side, SteamAPIWarningMessageHook_t pFunction)
 {
+    pFunction = (SteamAPIWarningMessageHook_t)manual_convert_SteamAPIWarningMessageHook_t((void*)pFunction);
     ((ISteamClient*)linux_side)->SetWarningMessageHook((SteamAPIWarningMessageHook_t)pFunction);
 }
 
diff --git a/lsteamclient/cppISteamClient_SteamClient014.cpp b/lsteamclient/cppISteamClient_SteamClient014.cpp
index 820d9d80..83847a00 100644
--- a/lsteamclient/cppISteamClient_SteamClient014.cpp
+++ b/lsteamclient/cppISteamClient_SteamClient014.cpp
@@ -117,6 +117,7 @@ uint32 cppISteamClient_SteamClient014_GetIPCCallCount(void *linux_side)
 
 void cppISteamClient_SteamClient014_SetWarningMessageHook(void *linux_side, SteamAPIWarningMessageHook_t pFunction)
 {
+    pFunction = (SteamAPIWarningMessageHook_t)manual_convert_SteamAPIWarningMessageHook_t((void*)pFunction);
     ((ISteamClient*)linux_side)->SetWarningMessageHook((SteamAPIWarningMessageHook_t)pFunction);
 }
 
diff --git a/lsteamclient/cppISteamClient_SteamClient015.cpp b/lsteamclient/cppISteamClient_SteamClient015.cpp
index b79fb6e1..1c0d59a0 100644
--- a/lsteamclient/cppISteamClient_SteamClient015.cpp
+++ b/lsteamclient/cppISteamClient_SteamClient015.cpp
@@ -117,6 +117,7 @@ uint32 cppISteamClient_SteamClient015_GetIPCCallCount(void *linux_side)
 
 void cppISteamClient_SteamClient015_SetWarningMessageHook(void *linux_side, SteamAPIWarningMessageHook_t pFunction)
 {
+    pFunction = (SteamAPIWarningMessageHook_t)manual_convert_SteamAPIWarningMessageHook_t((void*)pFunction);
     ((ISteamClient*)linux_side)->SetWarningMessageHook((SteamAPIWarningMessageHook_t)pFunction);
 }
 
diff --git a/lsteamclient/cppISteamClient_SteamClient016.cpp b/lsteamclient/cppISteamClient_SteamClient016.cpp
index 929b5a9d..636e323f 100644
--- a/lsteamclient/cppISteamClient_SteamClient016.cpp
+++ b/lsteamclient/cppISteamClient_SteamClient016.cpp
@@ -117,6 +117,7 @@ uint32 cppISteamClient_SteamClient016_GetIPCCallCount(void *linux_side)
 
 void cppISteamClient_SteamClient016_SetWarningMessageHook(void *linux_side, SteamAPIWarningMessageHook_t pFunction)
 {
+    pFunction = (SteamAPIWarningMessageHook_t)manual_convert_SteamAPIWarningMessageHook_t((void*)pFunction);
     ((ISteamClient*)linux_side)->SetWarningMessageHook((SteamAPIWarningMessageHook_t)pFunction);
 }
 
diff --git a/lsteamclient/cppISteamClient_SteamClient017.cpp b/lsteamclient/cppISteamClient_SteamClient017.cpp
index 5003ff8d..ddc292b7 100644
--- a/lsteamclient/cppISteamClient_SteamClient017.cpp
+++ b/lsteamclient/cppISteamClient_SteamClient017.cpp
@@ -117,6 +117,7 @@ uint32 cppISteamClient_SteamClient017_GetIPCCallCount(void *linux_side)
 
 void cppISteamClient_SteamClient017_SetWarningMessageHook(void *linux_side, SteamAPIWarningMessageHook_t pFunction)
 {
+    pFunction = (SteamAPIWarningMessageHook_t)manual_convert_SteamAPIWarningMessageHook_t((void*)pFunction);
     ((ISteamClient*)linux_side)->SetWarningMessageHook((SteamAPIWarningMessageHook_t)pFunction);
 }
 
diff --git a/lsteamclient/cppISteamClient_SteamClient018.cpp b/lsteamclient/cppISteamClient_SteamClient018.cpp
index ee779088..70aa6628 100644
--- a/lsteamclient/cppISteamClient_SteamClient018.cpp
+++ b/lsteamclient/cppISteamClient_SteamClient018.cpp
@@ -123,6 +123,7 @@ uint32 cppISteamClient_SteamClient018_GetIPCCallCount(void *linux_side)
 
 void cppISteamClient_SteamClient018_SetWarningMessageHook(void *linux_side, SteamAPIWarningMessageHook_t pFunction)
 {
+    pFunction = (SteamAPIWarningMessageHook_t)manual_convert_SteamAPIWarningMessageHook_t((void*)pFunction);
     ((ISteamClient*)linux_side)->SetWarningMessageHook((SteamAPIWarningMessageHook_t)pFunction);
 }
 
diff --git a/lsteamclient/cppISteamClient_SteamClient019.cpp b/lsteamclient/cppISteamClient_SteamClient019.cpp
index 6fb8f855..82a3b8e6 100644
--- a/lsteamclient/cppISteamClient_SteamClient019.cpp
+++ b/lsteamclient/cppISteamClient_SteamClient019.cpp
@@ -123,6 +123,7 @@ uint32 cppISteamClient_SteamClient019_GetIPCCallCount(void *linux_side)
 
 void cppISteamClient_SteamClient019_SetWarningMessageHook(void *linux_side, SteamAPIWarningMessageHook_t pFunction)
 {
+    pFunction = (SteamAPIWarningMessageHook_t)manual_convert_SteamAPIWarningMessageHook_t((void*)pFunction);
     ((ISteamClient*)linux_side)->SetWarningMessageHook((SteamAPIWarningMessageHook_t)pFunction);
 }
 
diff --git a/lsteamclient/cppISteamClient_SteamClient020.cpp b/lsteamclient/cppISteamClient_SteamClient020.cpp
index 65b81b98..4c87a239 100644
--- a/lsteamclient/cppISteamClient_SteamClient020.cpp
+++ b/lsteamclient/cppISteamClient_SteamClient020.cpp
@@ -123,6 +123,7 @@ uint32 cppISteamClient_SteamClient020_GetIPCCallCount(void *linux_side)
 
 void cppISteamClient_SteamClient020_SetWarningMessageHook(void *linux_side, SteamAPIWarningMessageHook_t pFunction)
 {
+    pFunction = (SteamAPIWarningMessageHook_t)manual_convert_SteamAPIWarningMessageHook_t((void*)pFunction);
     ((ISteamClient*)linux_side)->SetWarningMessageHook((SteamAPIWarningMessageHook_t)pFunction);
 }
 
diff --git a/lsteamclient/cppISteamUtils_SteamUtils004.cpp b/lsteamclient/cppISteamUtils_SteamUtils004.cpp
index 6f2a4706..4c01cd90 100644
--- a/lsteamclient/cppISteamUtils_SteamUtils004.cpp
+++ b/lsteamclient/cppISteamUtils_SteamUtils004.cpp
@@ -92,6 +92,7 @@ uint32 cppISteamUtils_SteamUtils004_GetIPCCallCount(void *linux_side)
 
 void cppISteamUtils_SteamUtils004_SetWarningMessageHook(void *linux_side, SteamAPIWarningMessageHook_t pFunction)
 {
+    pFunction = (SteamAPIWarningMessageHook_t)manual_convert_SteamAPIWarningMessageHook_t((void*)pFunction);
     ((ISteamUtils*)linux_side)->SetWarningMessageHook((SteamAPIWarningMessageHook_t)pFunction);
 }
 
diff --git a/lsteamclient/cppISteamUtils_SteamUtils005.cpp b/lsteamclient/cppISteamUtils_SteamUtils005.cpp
index d4faf857..fa64c145 100644
--- a/lsteamclient/cppISteamUtils_SteamUtils005.cpp
+++ b/lsteamclient/cppISteamUtils_SteamUtils005.cpp
@@ -92,6 +92,7 @@ uint32 cppISteamUtils_SteamUtils005_GetIPCCallCount(void *linux_side)
 
 void cppISteamUtils_SteamUtils005_SetWarningMessageHook(void *linux_side, SteamAPIWarningMessageHook_t pFunction)
 {
+    pFunction = (SteamAPIWarningMessageHook_t)manual_convert_SteamAPIWarningMessageHook_t((void*)pFunction);
     ((ISteamUtils*)linux_side)->SetWarningMessageHook((SteamAPIWarningMessageHook_t)pFunction);
 }
 
diff --git a/lsteamclient/cppISteamUtils_SteamUtils006.cpp b/lsteamclient/cppISteamUtils_SteamUtils006.cpp
index 483a303a..cf78566f 100644
--- a/lsteamclient/cppISteamUtils_SteamUtils006.cpp
+++ b/lsteamclient/cppISteamUtils_SteamUtils006.cpp
@@ -92,6 +92,7 @@ uint32 cppISteamUtils_SteamUtils006_GetIPCCallCount(void *linux_side)
 
 void cppISteamUtils_SteamUtils006_SetWarningMessageHook(void *linux_side, SteamAPIWarningMessageHook_t pFunction)
 {
+    pFunction = (SteamAPIWarningMessageHook_t)manual_convert_SteamAPIWarningMessageHook_t((void*)pFunction);
     ((ISteamUtils*)linux_side)->SetWarningMessageHook((SteamAPIWarningMessageHook_t)pFunction);
 }
 
diff --git a/lsteamclient/cppISteamUtils_SteamUtils007.cpp b/lsteamclient/cppISteamUtils_SteamUtils007.cpp
index 233d0a72..ba45950d 100644
--- a/lsteamclient/cppISteamUtils_SteamUtils007.cpp
+++ b/lsteamclient/cppISteamUtils_SteamUtils007.cpp
@@ -92,6 +92,7 @@ uint32 cppISteamUtils_SteamUtils007_GetIPCCallCount(void *linux_side)
 
 void cppISteamUtils_SteamUtils007_SetWarningMessageHook(void *linux_side, SteamAPIWarningMessageHook_t pFunction)
 {
+    pFunction = (SteamAPIWarningMessageHook_t)manual_convert_SteamAPIWarningMessageHook_t((void*)pFunction);
     ((ISteamUtils*)linux_side)->SetWarningMessageHook((SteamAPIWarningMessageHook_t)pFunction);
 }
 
diff --git a/lsteamclient/cppISteamUtils_SteamUtils008.cpp b/lsteamclient/cppISteamUtils_SteamUtils008.cpp
index c43ba3b8..87ab0ba4 100644
--- a/lsteamclient/cppISteamUtils_SteamUtils008.cpp
+++ b/lsteamclient/cppISteamUtils_SteamUtils008.cpp
@@ -92,6 +92,7 @@ uint32 cppISteamUtils_SteamUtils008_GetIPCCallCount(void *linux_side)
 
 void cppISteamUtils_SteamUtils008_SetWarningMessageHook(void *linux_side, SteamAPIWarningMessageHook_t pFunction)
 {
+    pFunction = (SteamAPIWarningMessageHook_t)manual_convert_SteamAPIWarningMessageHook_t((void*)pFunction);
     ((ISteamUtils*)linux_side)->SetWarningMessageHook((SteamAPIWarningMessageHook_t)pFunction);
 }
 
diff --git a/lsteamclient/cppISteamUtils_SteamUtils009.cpp b/lsteamclient/cppISteamUtils_SteamUtils009.cpp
index 8f0cf187..0af46f8b 100644
--- a/lsteamclient/cppISteamUtils_SteamUtils009.cpp
+++ b/lsteamclient/cppISteamUtils_SteamUtils009.cpp
@@ -93,6 +93,7 @@ uint32 cppISteamUtils_SteamUtils009_GetIPCCallCount(void *linux_side)
 
 void cppISteamUtils_SteamUtils009_SetWarningMessageHook(void *linux_side, SteamAPIWarningMessageHook_t pFunction)
 {
+    pFunction = (SteamAPIWarningMessageHook_t)manual_convert_SteamAPIWarningMessageHook_t((void*)pFunction);
     ((ISteamUtils*)linux_side)->SetWarningMessageHook((SteamAPIWarningMessageHook_t)pFunction);
 }
 
diff --git a/lsteamclient/cppISteamUtils_SteamUtils010.cpp b/lsteamclient/cppISteamUtils_SteamUtils010.cpp
index 4840406c..78554abf 100644
--- a/lsteamclient/cppISteamUtils_SteamUtils010.cpp
+++ b/lsteamclient/cppISteamUtils_SteamUtils010.cpp
@@ -93,6 +93,7 @@ uint32 cppISteamUtils_SteamUtils010_GetIPCCallCount(void *linux_side)
 
 void cppISteamUtils_SteamUtils010_SetWarningMessageHook(void *linux_side, SteamAPIWarningMessageHook_t pFunction)
 {
+    pFunction = (SteamAPIWarningMessageHook_t)manual_convert_SteamAPIWarningMessageHook_t((void*)pFunction);
     ((ISteamUtils*)linux_side)->SetWarningMessageHook((SteamAPIWarningMessageHook_t)pFunction);
 }
 
diff --git a/lsteamclient/gen_wrapper.py b/lsteamclient/gen_wrapper.py
index b3f48899..caa164f9 100755
--- a/lsteamclient/gen_wrapper.py
+++ b/lsteamclient/gen_wrapper.py
@@ -245,6 +245,7 @@ def method_needs_manual_handling(interface_with_version, method_name):
 # manual converters for simple types (function pointers)
 manual_type_converters = [
         "FSteamNetworkingSocketsDebugOutput",
+        "SteamAPIWarningMessageHook_t",
         "SteamAPI_CheckCallbackRegistered_t"
 ]
 
diff --git a/lsteamclient/steam_defs.h b/lsteamclient/steam_defs.h
index cc98181a..def82462 100644
--- a/lsteamclient/steam_defs.h
+++ b/lsteamclient/steam_defs.h
@@ -235,7 +235,7 @@ typedef struct SteamNetConnectionRealTimeLaneStatus_t SteamNetConnectionRealTime
 typedef struct SteamNetworkingFakeIPResult_t SteamNetworkingFakeIPResult_t;
 
 typedef uint32 (*SteamAPI_CheckCallbackRegistered_t)(int cb);
-typedef void *SteamAPIWarningMessageHook_t; //already cdecl, no need for conversion(?)
+typedef void *SteamAPIWarningMessageHook_t;
 typedef void *SteamAPI_PostAPIResultInProcess_t; //unused
 typedef void (*FSteamNetworkingSocketsDebugOutput)(ESteamNetworkingSocketsDebugOutputType nType, const char *pszMsg);
 
diff --git a/lsteamclient/steamclient_main.c b/lsteamclient/steamclient_main.c
index 88dbab3b..b64db0f2 100644
--- a/lsteamclient/steamclient_main.c
+++ b/lsteamclient/steamclient_main.c
@@ -692,6 +692,7 @@ static void callback_complete(UINT64 cookie)
 
 typedef void (WINAPI *win_FSteamNetworkingSocketsDebugOutput)(ESteamNetworkingSocketsDebugOutputType nType,
         const char *pszMsg);
+typedef void (CDECL *win_SteamAPIWarningMessageHook_t)(int, const char *pszMsg);
 
 static DWORD WINAPI callback_thread(void *dummy)
 {
@@ -710,6 +711,15 @@ static DWORD WINAPI callback_thread(void *dummy)
                         cb_data.sockets_debug_output.msg);
                 callback_complete(cookie);
                 break;
+            case STEAM_API_WARNING_HOOK:
+                TRACE("STEAM_API_WARNING_HOOK func %p, type %u, msg %s.\n",
+                        cb_data.func, cb_data.steam_api_warning_hook.severity,
+                        wine_dbgstr_a(cb_data.steam_api_warning_hook.msg));
+                ((win_SteamAPIWarningMessageHook_t)cb_data.func)(cb_data.steam_api_warning_hook.severity,
+                        cb_data.steam_api_warning_hook.msg);
+                callback_complete(cookie);
+                break;
+
             default:
                 ERR("Unexpected callback type %u.\n", cb_data.type);
                 break;
diff --git a/lsteamclient/steamclient_private.h b/lsteamclient/steamclient_private.h
index 2dc5799e..e383bfcc 100644
--- a/lsteamclient/steamclient_private.h
+++ b/lsteamclient/steamclient_private.h
@@ -59,6 +59,7 @@ void *create_LinuxISteamMatchmakingServerListResponse(void *win, const char *ver
 void *create_LinuxISteamMatchmakingPingResponse(void *win, const char *version);
 void *create_LinuxISteamMatchmakingPlayersResponse(void *win, const char *version);
 void *create_LinuxISteamMatchmakingRulesResponse(void *win, const char *version);
+void *manual_convert_SteamAPIWarningMessageHook_t(void *win_func);
 void *manual_convert_FSteamNetworkingSocketsDebugOutput(void *win_func);
 void *manual_convert_SteamAPI_CheckCallbackRegistered_t(void *win_func);
 
@@ -73,6 +74,7 @@ void *alloc_vtable(void *vtable, unsigned int method_count, const char *iface_ve
 enum callback_type
 {
     SOCKET_DEBUG_OUTPUT = 1,
+    STEAM_API_WARNING_HOOK,
 };
 
 struct callback_data
@@ -88,6 +90,12 @@ struct callback_data
             const char *msg;
         }
         sockets_debug_output;
+        struct
+        {
+            int severity;
+            const char *msg;
+        }
+        steam_api_warning_hook;
     };
 };
 
diff --git a/lsteamclient/steamclient_wrappers.c b/lsteamclient/steamclient_wrappers.c
index adb35391..f840752a 100644
--- a/lsteamclient/steamclient_wrappers.c
+++ b/lsteamclient/steamclient_wrappers.c
@@ -315,6 +315,29 @@ void *manual_convert_FSteamNetworkingSocketsDebugOutput(void *win_func)
 }
 
 
+static void *stored_SteamAPIWarningMessageHook_t;
+
+static void lin_SteamAPIWarningMessageHook_t(int severity, const char *msg)
+{
+    struct callback_data cb_data = { 0 };
+    /* Only Unix native calls from here (not even TRACE):
+     * this is native Unix thread which is not initialized by Wine. */
+    cb_data.type = STEAM_API_WARNING_HOOK;
+    cb_data.func = stored_SteamAPIWarningMessageHook_t;
+    cb_data.steam_api_warning_hook.severity = severity;
+    cb_data.steam_api_warning_hook.msg = msg;
+    execute_callback(&cb_data);
+}
+
+void *manual_convert_SteamAPIWarningMessageHook_t(void *win_func)
+{
+    TRACE("win_func %p, returning %p.\n", win_func, lin_SteamAPIWarningMessageHook_t);
+
+    stored_SteamAPIWarningMessageHook_t = win_func;
+
+    return &lin_SteamAPIWarningMessageHook_t;
+}
+
 /***** SteamAPI_CheckCallbackRegistered_t *****/
 static uint32 (__attribute__((ms_abi)) *stored_SteamAPI_CheckCallbackRegistered_t)(int cb);