diff --git a/dlls/api-ms-win-crt-runtime-l1-1-0/api-ms-win-crt-runtime-l1-1-0.spec b/dlls/api-ms-win-crt-runtime-l1-1-0/api-ms-win-crt-runtime-l1-1-0.spec
index 6afa0423858..65a73adc40e 100644
--- a/dlls/api-ms-win-crt-runtime-l1-1-0/api-ms-win-crt-runtime-l1-1-0.spec
+++ b/dlls/api-ms-win-crt-runtime-l1-1-0/api-ms-win-crt-runtime-l1-1-0.spec
@@ -30,7 +30,7 @@
 @ cdecl _controlfp_s(ptr long long) ucrtbase._controlfp_s
 @ stub _crt_at_quick_exit
 @ cdecl _crt_atexit(ptr) ucrtbase._crt_atexit
-@ stub _crt_debugger_hook
+@ cdecl _crt_debugger_hook(long) ucrtbase._crt_debugger_hook
 @ cdecl _endthread() ucrtbase._endthread
 @ cdecl _endthreadex(long) ucrtbase._endthreadex
 @ cdecl _errno() ucrtbase._errno
diff --git a/dlls/msvcr100/msvcr100.spec b/dlls/msvcr100/msvcr100.spec
index d8627d20fe3..39742aaa448 100644
--- a/dlls/msvcr100/msvcr100.spec
+++ b/dlls/msvcr100/msvcr100.spec
@@ -745,7 +745,8 @@
 @ cdecl _cputws(wstr)
 @ cdecl _creat(str long) MSVCRT__creat
 @ cdecl _create_locale(long str) MSVCRT__create_locale
-@ stub _crt_debugger_hook
+@ cdecl -arch=i386 _crt_debugger_hook(long) MSVCRT__crt_debugger_hook
+@ cdecl -arch=arm,win64 __crt_debugger_hook(long) MSVCRT__crt_debugger_hook
 @ varargs _cscanf(str)
 @ varargs _cscanf_l(str ptr)
 @ varargs _cscanf_s(str)
diff --git a/dlls/msvcr110/msvcr110.spec b/dlls/msvcr110/msvcr110.spec
index bf82d30c481..dd23c750353 100644
--- a/dlls/msvcr110/msvcr110.spec
+++ b/dlls/msvcr110/msvcr110.spec
@@ -1093,8 +1093,8 @@
 @ cdecl _cputws(wstr)
 @ cdecl _creat(str long) MSVCRT__creat
 @ cdecl _create_locale(long str) MSVCRT__create_locale
-@ stub -arch=i386 _crt_debugger_hook
-@ stub -arch=arm,win64 __crt_debugger_hook
+@ cdecl -arch=i386 _crt_debugger_hook(long) MSVCRT__crt_debugger_hook
+@ cdecl -arch=arm,win64 __crt_debugger_hook(long) MSVCRT__crt_debugger_hook
 @ varargs _cscanf(str)
 @ varargs _cscanf_l(str ptr)
 @ varargs _cscanf_s(str)
diff --git a/dlls/msvcr120/msvcr120.spec b/dlls/msvcr120/msvcr120.spec
index 69cb2c1e1af..461b5299730 100644
--- a/dlls/msvcr120/msvcr120.spec
+++ b/dlls/msvcr120/msvcr120.spec
@@ -1084,8 +1084,8 @@
 @ cdecl _cputws(wstr)
 @ cdecl _creat(str long) MSVCRT__creat
 @ cdecl _create_locale(long str) MSVCRT__create_locale
-@ stub -arch=i386 _crt_debugger_hook
-@ stub -arch=arm,win64 __crt_debugger_hook
+@ cdecl -arch=i386 _crt_debugger_hook(long) MSVCRT__crt_debugger_hook
+@ cdecl -arch=arm,win64 __crt_debugger_hook(long) MSVCRT__crt_debugger_hook
 @ varargs _cscanf(str)
 @ varargs _cscanf_l(str ptr)
 @ varargs _cscanf_s(str)
diff --git a/dlls/msvcr120_app/msvcr120_app.spec b/dlls/msvcr120_app/msvcr120_app.spec
index 1e4554f20e6..425c839b691 100644
--- a/dlls/msvcr120_app/msvcr120_app.spec
+++ b/dlls/msvcr120_app/msvcr120_app.spec
@@ -1038,8 +1038,8 @@
 @ cdecl _copysignf(float float) msvcr120._copysignf
 @ cdecl _creat(str long) msvcr120._creat
 @ cdecl _create_locale(long str) msvcr120._create_locale
-@ stub -arch=i386 _crt_debugger_hook
-@ stub -arch=arm,win64 __crt_debugger_hook
+@ cdecl -arch=i386 _crt_debugger_hook(long) msvcr120._crt_debugger_hook
+@ cdecl -arch=arm,win64 __crt_debugger_hook(long) msvcr120.__crt_debugger_hook
 @ cdecl _ctime32(ptr) msvcr120._ctime32
 @ cdecl _ctime32_s(str long ptr) msvcr120._ctime32_s
 @ cdecl _ctime64(ptr) msvcr120._ctime64
diff --git a/dlls/msvcr80/msvcr80.spec b/dlls/msvcr80/msvcr80.spec
index 510703825d4..17af90b9ba6 100644
--- a/dlls/msvcr80/msvcr80.spec
+++ b/dlls/msvcr80/msvcr80.spec
@@ -409,8 +409,8 @@
 @ cdecl _cputws(wstr)
 @ cdecl _creat(str long) MSVCRT__creat
 @ cdecl _create_locale(long str) MSVCRT__create_locale
-@ stub -arch=i386 _crt_debugger_hook
-@ stub -arch=arm,win64 __crt_debugger_hook
+@ cdecl -arch=i386 _crt_debugger_hook(long) MSVCRT__crt_debugger_hook
+@ cdecl -arch=arm,win64 __crt_debugger_hook(long) MSVCRT__crt_debugger_hook
 @ varargs _cscanf(str)
 @ varargs _cscanf_l(str ptr)
 @ varargs _cscanf_s(str)
diff --git a/dlls/msvcr90/msvcr90.spec b/dlls/msvcr90/msvcr90.spec
index 30bfbcd379d..fd08455e8ba 100644
--- a/dlls/msvcr90/msvcr90.spec
+++ b/dlls/msvcr90/msvcr90.spec
@@ -392,7 +392,8 @@
 @ cdecl _cputws(wstr)
 @ cdecl _creat(str long) MSVCRT__creat
 @ cdecl _create_locale(long str) MSVCRT__create_locale
-@ stub _crt_debugger_hook
+@ cdecl -arch=i386 _crt_debugger_hook(long) MSVCRT__crt_debugger_hook
+@ cdecl -arch=arm,win64 __crt_debugger_hook(long) MSVCRT__crt_debugger_hook
 @ varargs _cscanf(str)
 @ varargs _cscanf_l(str ptr)
 @ varargs _cscanf_s(str)
diff --git a/dlls/msvcrt/misc.c b/dlls/msvcrt/misc.c
index 4e9f2889dee..c1510ef6cad 100644
--- a/dlls/msvcrt/misc.c
+++ b/dlls/msvcrt/misc.c
@@ -498,3 +498,11 @@ void CDECL MSVCR120__vacopy(__ms_va_list *dest, __ms_va_list src)
 {
     __ms_va_copy(*dest, src);
 }
+
+/*********************************************************************
+ * _crt_debugger_hook (MSVCR80.@)
+ */
+void CDECL MSVCRT__crt_debugger_hook(int reserved)
+{
+    WARN("(%x)\n", reserved);
+}
diff --git a/dlls/ucrtbase/ucrtbase.spec b/dlls/ucrtbase/ucrtbase.spec
index e65a1c09dff..e59e26fbfe8 100644
--- a/dlls/ucrtbase/ucrtbase.spec
+++ b/dlls/ucrtbase/ucrtbase.spec
@@ -242,7 +242,7 @@
 @ cdecl _create_locale(long str) MSVCRT__create_locale
 @ stub _crt_at_quick_exit
 @ cdecl _crt_atexit(ptr) MSVCRT__crt_atexit
-@ stub _crt_debugger_hook
+@ cdecl _crt_debugger_hook(long) MSVCRT__crt_debugger_hook
 @ cdecl _ctime32(ptr) MSVCRT__ctime32
 @ cdecl _ctime32_s(str long ptr) MSVCRT__ctime32_s
 @ cdecl _ctime64(ptr) MSVCRT__ctime64