--- a/dlls/x3daudio1_0/x3daudio1_0.spec	2019-08-30 22:11:51.000000000 +0200
+++ b/dlls/x3daudio1_0/x3daudio1_0.spec	2019-09-24 13:02:59.151295631 +0200
@@ -1,2 +1,2 @@
-@ cdecl X3DAudioCalculate(ptr ptr ptr long ptr)
-@ cdecl X3DAudioInitialize(long float ptr) LEGACY_X3DAudioInitialize
+@ stdcall _X3DAudioCalculate@20(ptr ptr ptr long ptr) X3DAudioCalculate
+@ stdcall _X3DAudioInitialize@12(long float ptr) LEGACY_X3DAudioInitialize
--- a/dlls/x3daudio1_1/x3daudio1_1.spec	2019-08-30 22:11:51.000000000 +0200
+++ b/dlls/x3daudio1_1/x3daudio1_1.spec	2019-09-24 13:02:59.151295631 +0200
@@ -1,2 +1,2 @@
-@ cdecl X3DAudioCalculate(ptr ptr ptr long ptr)
-@ cdecl X3DAudioInitialize(long float ptr) LEGACY_X3DAudioInitialize
+@ stdcall _X3DAudioCalculate@20(ptr ptr ptr long ptr) X3DAudioCalculate
+@ stdcall _X3DAudioInitialize@12(long float ptr) LEGACY_X3DAudioInitialize
--- a/dlls/x3daudio1_2/x3daudio1_2.spec	2019-08-30 22:11:51.000000000 +0200
+++ b/dlls/x3daudio1_2/x3daudio1_2.spec	2019-09-24 13:02:59.151295631 +0200
@@ -1,2 +1,2 @@
-@ cdecl X3DAudioCalculate(ptr ptr ptr long ptr)
-@ cdecl X3DAudioInitialize(long float ptr) LEGACY_X3DAudioInitialize
+@ stdcall _X3DAudioCalculate@20(ptr ptr ptr long ptr) X3DAudioCalculate
+@ stdcall _X3DAudioInitialize@12(long float ptr) LEGACY_X3DAudioInitialize
--- a/dlls/x3daudio1_3/x3daudio1_3.spec	2019-08-30 22:11:51.000000000 +0200
+++ b/dlls/x3daudio1_3/x3daudio1_3.spec	2019-09-24 13:02:59.151295631 +0200
@@ -1,2 +1,2 @@
-@ cdecl X3DAudioCalculate(ptr ptr ptr long ptr)
-@ cdecl X3DAudioInitialize(long float ptr) LEGACY_X3DAudioInitialize
+@ stdcall X3DAudioCalculate(ptr ptr ptr long ptr) X3DAudioCalculate
+@ stdcall X3DAudioInitialize(long float ptr) LEGACY_X3DAudioInitialize
--- a/dlls/x3daudio1_4/x3daudio1_4.spec	2019-08-30 22:11:51.000000000 +0200
+++ b/dlls/x3daudio1_4/x3daudio1_4.spec	2019-09-24 13:02:59.151295631 +0200
@@ -1,2 +1,2 @@
-@ cdecl X3DAudioCalculate(ptr ptr ptr long ptr)
-@ cdecl X3DAudioInitialize(long float ptr) LEGACY_X3DAudioInitialize
+@ stdcall X3DAudioCalculate(ptr ptr ptr long ptr) X3DAudioCalculate
+@ stdcall X3DAudioInitialize(long float ptr) LEGACY_X3DAudioInitialize
--- a/dlls/x3daudio1_5/x3daudio1_5.spec	2019-08-30 22:11:51.000000000 +0200
+++ b/dlls/x3daudio1_5/x3daudio1_5.spec	2019-09-24 13:02:59.151295631 +0200
@@ -1,2 +1,2 @@
-@ cdecl X3DAudioCalculate(ptr ptr ptr long ptr)
-@ cdecl X3DAudioInitialize(long float ptr) LEGACY_X3DAudioInitialize
+@ stdcall X3DAudioCalculate(ptr ptr ptr long ptr) X3DAudioCalculate
+@ stdcall X3DAudioInitialize(long float ptr) LEGACY_X3DAudioInitialize
--- a/dlls/x3daudio1_6/x3daudio1_6.spec	2019-08-30 22:11:51.000000000 +0200
+++ b/dlls/x3daudio1_6/x3daudio1_6.spec	2019-09-24 13:02:59.151295631 +0200
@@ -1,2 +1,2 @@
-@ cdecl X3DAudioCalculate(ptr ptr ptr long ptr)
-@ cdecl X3DAudioInitialize(long float ptr) LEGACY_X3DAudioInitialize
+@ stdcall X3DAudioCalculate(ptr ptr ptr long ptr) X3DAudioCalculate
+@ stdcall X3DAudioInitialize(long float ptr) LEGACY_X3DAudioInitialize
--- a/dlls/x3daudio1_7/x3daudio1_7.spec	2019-08-30 22:11:51.000000000 +0200
+++ b/dlls/x3daudio1_7/x3daudio1_7.spec	2019-09-24 13:02:59.151295631 +0200
@@ -1,2 +1,2 @@
-@ cdecl X3DAudioCalculate(ptr ptr ptr long ptr)
-@ cdecl X3DAudioInitialize(long float ptr) LEGACY_X3DAudioInitialize
+@ stdcall X3DAudioCalculate(ptr ptr ptr long ptr) X3DAudioCalculate
+@ stdcall X3DAudioInitialize(long float ptr) LEGACY_X3DAudioInitialize
--- a/dlls/xaudio2_7/x3daudio.c	2019-08-30 22:11:51.000000000 +0200
+++ b/dlls/xaudio2_7/x3daudio.c	2019-09-24 14:18:33.519066671 +0200
@@ -49,7 +49,7 @@ BOOL WINAPI DllMain(HINSTANCE hinstDLL,
 #endif /* X3DAUDIO1_VER */
 
 #if XAUDIO2_VER >= 8
-HRESULT CDECL X3DAudioInitialize(UINT32 chanmask, float speedofsound,
+HRESULT WINAPI X3DAudioInitialize(UINT32 chanmask, float speedofsound,
         X3DAUDIO_HANDLE handle)
 {
     TRACE("0x%x, %f, %p\n", chanmask, speedofsound, handle);
@@ -63,7 +63,7 @@ HRESULT CDECL X3DAudioInitialize(UINT32
 #endif /* XAUDIO2_VER >= 8 */
 
 #ifdef X3DAUDIO1_VER
-void CDECL LEGACY_X3DAudioInitialize(UINT32 chanmask, float speedofsound,
+void WINAPI LEGACY_X3DAudioInitialize(UINT32 chanmask, float speedofsound,
         X3DAUDIO_HANDLE handle)
 {
     TRACE("0x%x, %f, %p\n", chanmask, speedofsound, handle);
@@ -72,7 +72,7 @@ void CDECL LEGACY_X3DAudioInitialize(UIN
 #endif /* X3DAUDIO1_VER */
 
 #if XAUDIO2_VER >= 8 || defined X3DAUDIO1_VER
-void CDECL X3DAudioCalculate(const X3DAUDIO_HANDLE handle,
+void WINAPI X3DAudioCalculate(const X3DAUDIO_HANDLE handle,
         const X3DAUDIO_LISTENER *listener, const X3DAUDIO_EMITTER *emitter,
         UINT32 flags, X3DAUDIO_DSP_SETTINGS *out)
 {
--- a/include/x3daudio.h	2019-08-30 22:11:51.000000000 +0200
+++ b/include/x3daudio.h	2019-09-24 14:32:32.107311670 +0200
@@ -90,8 +90,8 @@ typedef struct X3DAUDIO_DSP_SETTINGS {
 #define X3DAUDIO_HANDLE_BYTESIZE 20
 typedef BYTE X3DAUDIO_HANDLE[X3DAUDIO_HANDLE_BYTESIZE];
 
-HRESULT CDECL X3DAudioInitialize(UINT32, float, X3DAUDIO_HANDLE);
-void CDECL X3DAudioCalculate(const X3DAUDIO_HANDLE, const X3DAUDIO_LISTENER *,
+HRESULT WINAPI X3DAudioInitialize(UINT32, float, X3DAUDIO_HANDLE);
+void WINAPI X3DAudioCalculate(const X3DAUDIO_HANDLE, const X3DAUDIO_LISTENER *,
         const X3DAUDIO_EMITTER *, UINT32, X3DAUDIO_DSP_SETTINGS *);
 
 #endif