diff --git a/audio/out/ao_dsound.c b/audio/out/ao_dsound.c
index b5d8c61bcc..825e3095df 100644
--- a/audio/out/ao_dsound.c
+++ b/audio/out/ao_dsound.c
@@ -228,7 +228,7 @@ static int LoadDirectSound(struct ao *ao)
     struct priv *p = ao->priv;
 
     // initialize directsound
-    p->hdsound_dll = LoadLibrary("DSOUND.DLL");
+    p->hdsound_dll = LoadLibrary(L"DSOUND.DLL");
     if (p->hdsound_dll == NULL) {
         MP_ERR(ao, "cannot load DSOUND.DLL\n");
         return 0;
diff --git a/audio/out/ao_wasapi.c b/audio/out/ao_wasapi.c
index 8fb8a71fb9..1b99c4136a 100644
--- a/audio/out/ao_wasapi.c
+++ b/audio/out/ao_wasapi.c
@@ -17,9 +17,6 @@
  * with mpv.  If not, see <http://www.gnu.org/licenses/>.
  */
 
-#define COBJMACROS 1
-#define _WIN32_WINNT 0x600
-
 #include <stdlib.h>
 #include <inttypes.h>
 #include <process.h>
diff --git a/audio/out/ao_wasapi.h b/audio/out/ao_wasapi.h
index 367aae03aa..895497bffb 100755
--- a/audio/out/ao_wasapi.h
+++ b/audio/out/ao_wasapi.h
@@ -20,9 +20,6 @@
 #ifndef MP_AO_WASAPI_H_
 #define MP_AO_WASAPI_H_
 
-#define COBJMACROS 1
-#define _WIN32_WINNT 0x600
-
 #include <audioclient.h>
 #include <audiopolicy.h>
 #include <mmdeviceapi.h>
diff --git a/audio/out/ao_wasapi_changenotify.c b/audio/out/ao_wasapi_changenotify.c
index cd869c7ab5..ea7e2c6aa7 100755
--- a/audio/out/ao_wasapi_changenotify.c
+++ b/audio/out/ao_wasapi_changenotify.c
@@ -17,9 +17,6 @@
  * with mpv.  If not, see <http://www.gnu.org/licenses/>.
  */
 
-#define COBJMACROS 1
-#define _WIN32_WINNT 0x600
-
 #include <initguid.h>
 #include <audioclient.h>
 #include <endpointvolume.h>
diff --git a/audio/out/ao_wasapi_utils.c b/audio/out/ao_wasapi_utils.c
index 072e80e208..30f1f38ae8 100755
--- a/audio/out/ao_wasapi_utils.c
+++ b/audio/out/ao_wasapi_utils.c
@@ -17,9 +17,6 @@
  * with mpv.  If not, see <http://www.gnu.org/licenses/>.
  */
 
-#define COBJMACROS 1
-#define _WIN32_WINNT 0x600
-
 #include <math.h>
 #include <libavutil/common.h>
 #include <initguid.h>
diff --git a/osdep/subprocess-win.c b/osdep/subprocess-win.c
index 9edfca0f45..fc5db081f8 100644
--- a/osdep/subprocess-win.c
+++ b/osdep/subprocess-win.c
@@ -15,7 +15,6 @@
  * with mpv.  If not, see <http://www.gnu.org/licenses/>.
  */
 
-#define _WIN32_WINNT 0x0600
 #include <windows.h>
 #include <string.h>
 
diff --git a/video/decode/dxva2.c b/video/decode/dxva2.c
index 405ad293b4..cbd08a7e52 100644
--- a/video/decode/dxva2.c
+++ b/video/decode/dxva2.c
@@ -21,12 +21,7 @@
 
 #include <windows.h>
 
-#ifdef _WIN32_WINNT
-#undef _WIN32_WINNT
-#endif
-#define _WIN32_WINNT 0x0600
 #define DXVA2API_USE_BITFIELDS
-#define COBJMACROS
 
 #include <stdint.h>
 
@@ -360,12 +355,12 @@ static int dxva2_init(struct lavc_ctx *s)
 
     ctx->deviceHandle = INVALID_HANDLE_VALUE;
 
-    ctx->d3dlib = LoadLibrary("d3d9.dll");
+    ctx->d3dlib = LoadLibrary(L"d3d9.dll");
     if (!ctx->d3dlib) {
         MP_ERR(ctx, "Failed to load D3D9 library\n");
         goto fail;
     }
-    ctx->dxva2lib = LoadLibrary("dxva2.dll");
+    ctx->dxva2lib = LoadLibrary(L"dxva2.dll");
     if (!ctx->dxva2lib) {
         MP_ERR(ctx, "Failed to load DXVA2 library\n");
         goto fail;
diff --git a/video/filter/vf_dlopen.c b/video/filter/vf_dlopen.c
index 7e546df32f..00e6245a2e 100644
--- a/video/filter/vf_dlopen.c
+++ b/video/filter/vf_dlopen.c
@@ -34,7 +34,7 @@
 
 #ifdef _WIN32
 # include <windows.h>
-# define DLLOpen(name)           LoadLibrary(name)
+# define DLLOpen(name)           LoadLibraryA(name)
 # define DLLClose(handle)        FreeLibrary(handle)
 # define DLLSymbol(handle, name) ((void *)GetProcAddress(handle, name))
 #else
diff --git a/video/out/gl_w32.c b/video/out/gl_w32.c
index 79e3165b39..abdea60775 100644
--- a/video/out/gl_w32.c
+++ b/video/out/gl_w32.c
@@ -81,7 +81,7 @@ static void *w32gpa(const GLubyte *procName)
     void *res = wglGetProcAddress(procName);
     if (res)
         return res;
-    oglmod = GetModuleHandle("opengl32.dll");
+    oglmod = GetModuleHandle(L"opengl32.dll");
     return GetProcAddress(oglmod, procName);
 }
 
diff --git a/video/out/w32_common.c b/video/out/w32_common.c
index 672c61150e..bcfe0dbff0 100644
--- a/video/out/w32_common.c
+++ b/video/out/w32_common.c
@@ -16,8 +16,6 @@
  * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
  */
 
-#define COBJMACROS
-#define _WIN32_WINNT 0x0600
 #include <stdio.h>
 #include <limits.h>
 #include <pthread.h>
diff --git a/waftools/checks/custom.py b/waftools/checks/custom.py
index 365c388800..fb45d8697c 100644
--- a/waftools/checks/custom.py
+++ b/waftools/checks/custom.py
@@ -24,7 +24,7 @@ def check_pthreads(ctx, dependency_identifier):
         h = ctx.path.find_node('osdep/win32/include').abspath()
         # define IN_WINPTHREAD to workaround mingw stupidity (we never want it
         # to define features specific to its own pthread stuff)
-        ctx.env.CFLAGS += ['-isystem', h, '-I', h, '-D_WIN32_WINNT=0x600', '-DIN_WINPTHREAD']
+        ctx.env.CFLAGS += ['-isystem', h, '-I', h, '-DIN_WINPTHREAD']
         return True
     if check_pthread_flag(ctx, dependency_identifier):
         return True
diff --git a/waftools/detections/compiler.py b/waftools/detections/compiler.py
index 53b7d24892..a43a713de1 100644
--- a/waftools/detections/compiler.py
+++ b/waftools/detections/compiler.py
@@ -47,11 +47,16 @@ def __add_clang_flags__(ctx):
                        "-Wno-tautological-compare",
                        "-Wno-tautological-constant-out-of-range-compare" ]
 
+def __add_mswin_flags__(ctx):
+    ctx.env.CFLAGS += ['-D_WIN32_WINNT=0x600', '-DUNICODE', '-DCOBJMACROS']
+
 def __add_mingw_flags__(ctx):
+    __add_mswin_flags__(ctx)
     ctx.env.CFLAGS += ['-D__USE_MINGW_ANSI_STDIO=1']
     ctx.env.LAST_LINKFLAGS += ['-mwindows']
 
 def __add_cygwin_flags__(ctx):
+    __add_mswin_flags__(ctx)
     ctx.env.CFLAGS += ['-mwin32']
     ctx.env.CFLAGS += ['-U__STRICT_ANSI__']
 
diff --git a/waftools/fragments/wasapi.c b/waftools/fragments/wasapi.c
index ef3b3f7866..5528ce171b 100644
--- a/waftools/fragments/wasapi.c
+++ b/waftools/fragments/wasapi.c
@@ -1,5 +1,3 @@
-#define COBJMACROS 1
-#define _WIN32_WINNT 0x600
 #include <malloc.h>
 #include <stdlib.h>
 #include <process.h>