diff --git a/dlls/api-ms-win-core-com-l1-1-0/api-ms-win-core-com-l1-1-0.spec b/dlls/api-ms-win-core-com-l1-1-0/api-ms-win-core-com-l1-1-0.spec
index f645c9d1d05..954d6dae020 100644
--- a/dlls/api-ms-win-core-com-l1-1-0/api-ms-win-core-com-l1-1-0.spec
+++ b/dlls/api-ms-win-core-com-l1-1-0/api-ms-win-core-com-l1-1-0.spec
@@ -49,7 +49,7 @@
 @ stdcall CoQueryProxyBlanket(ptr ptr ptr ptr ptr ptr ptr ptr) ole32.CoQueryProxyBlanket
 @ stdcall CoRegisterClassObject(ptr ptr long long ptr) ole32.CoRegisterClassObject
 @ stdcall CoRegisterPSClsid(ptr ptr) ole32.CoRegisterPSClsid
-@ stub CoRegisterSurrogate
+@ stdcall CoRegisterSurrogate(ptr) ole32.CoRegisterSurrogate
 @ stdcall CoReleaseMarshalData(ptr) ole32.CoReleaseMarshalData
 @ stdcall CoReleaseServerProcess() ole32.CoReleaseServerProcess
 @ stdcall CoResumeClassObjects() ole32.CoResumeClassObjects
diff --git a/dlls/api-ms-win-core-com-l1-1-1/api-ms-win-core-com-l1-1-1.spec b/dlls/api-ms-win-core-com-l1-1-1/api-ms-win-core-com-l1-1-1.spec
index d2914f0c8b8..a124d34f0e2 100644
--- a/dlls/api-ms-win-core-com-l1-1-1/api-ms-win-core-com-l1-1-1.spec
+++ b/dlls/api-ms-win-core-com-l1-1-1/api-ms-win-core-com-l1-1-1.spec
@@ -50,7 +50,7 @@
 @ stub CoRegisterActivationFilter
 @ stdcall CoRegisterClassObject(ptr ptr long long ptr) ole32.CoRegisterClassObject
 @ stdcall CoRegisterPSClsid(ptr ptr) ole32.CoRegisterPSClsid
-@ stub CoRegisterSurrogate
+@ stdcall CoRegisterSurrogate(ptr) ole32.CoRegisterSurrogate
 @ stdcall CoReleaseMarshalData(ptr) ole32.CoReleaseMarshalData
 @ stdcall CoReleaseServerProcess() ole32.CoReleaseServerProcess
 @ stdcall CoResumeClassObjects() ole32.CoResumeClassObjects
diff --git a/dlls/api-ms-win-core-com-private-l1-1-0/api-ms-win-core-com-private-l1-1-0.spec b/dlls/api-ms-win-core-com-private-l1-1-0/api-ms-win-core-com-private-l1-1-0.spec
index 14d3b27604b..13ee6012a9e 100644
--- a/dlls/api-ms-win-core-com-private-l1-1-0/api-ms-win-core-com-private-l1-1-0.spec
+++ b/dlls/api-ms-win-core-com-private-l1-1-0/api-ms-win-core-com-private-l1-1-0.spec
@@ -22,7 +22,7 @@
 @ stdcall CoRegisterInitializeSpy(ptr ptr) ole32.CoRegisterInitializeSpy
 @ stdcall CoRegisterMallocSpy(ptr) ole32.CoRegisterMallocSpy
 @ stdcall CoRegisterMessageFilter(ptr ptr) ole32.CoRegisterMessageFilter
-@ stub CoRegisterSurrogateEx
+@ stdcall CoRegisterSurrogateEx(ptr ptr) ole32.CoRegisterSurrogateEx
 @ stub CoRetireServer
 @ stdcall CoRevokeInitializeSpy(int64) ole32.CoRevokeInitializeSpy
 @ stdcall CoRevokeMallocSpy() ole32.CoRevokeMallocSpy
diff --git a/dlls/combase/combase.spec b/dlls/combase/combase.spec
index b612bef9c57..493e7968d12 100644
--- a/dlls/combase/combase.spec
+++ b/dlls/combase/combase.spec
@@ -138,8 +138,8 @@
 @ stdcall CoRegisterMallocSpy(ptr) ole32.CoRegisterMallocSpy
 @ stdcall CoRegisterMessageFilter(ptr ptr) ole32.CoRegisterMessageFilter
 @ stdcall CoRegisterPSClsid(ptr ptr) ole32.CoRegisterPSClsid
-@ stub CoRegisterSurrogate
-@ stub CoRegisterSurrogateEx
+@ stdcall CoRegisterSurrogate(ptr) ole32.CoRegisterSurrogate
+@ stdcall CoRegisterSurrogateEx(ptr ptr) ole32.CoRegisterSurrogateEx
 @ stdcall CoReleaseMarshalData(ptr) ole32.CoReleaseMarshalData
 @ stdcall CoReleaseServerProcess() ole32.CoReleaseServerProcess
 @ stdcall CoResumeClassObjects() ole32.CoResumeClassObjects
diff --git a/dlls/ole32/compobj.c b/dlls/ole32/compobj.c
index 7dd10a79942..1ce9cec6e53 100644
--- a/dlls/ole32/compobj.c
+++ b/dlls/ole32/compobj.c
@@ -5074,6 +5074,26 @@ HRESULT WINAPI CoGetApartmentType(APTTYPE *type, APTTYPEQUALIFIER *qualifier)
     return info->apt ? S_OK : CO_E_NOTINITIALIZED;
 }
 
+/***********************************************************************
+ *           CoRegisterSurrogate [OLE32.@]
+ */
+HRESULT WINAPI CoRegisterSurrogate(ISurrogate *surrogate)
+{
+    FIXME("(%p): stub\n", surrogate);
+
+    return E_NOTIMPL;
+}
+
+/***********************************************************************
+ *           CoRegisterSurrogateEx [OLE32.@]
+ */
+HRESULT WINAPI CoRegisterSurrogateEx(REFGUID guid, void *reserved)
+{
+    FIXME("(%s %p): stub\n", debugstr_guid(guid), reserved);
+
+    return E_NOTIMPL;
+}
+
 typedef struct {
     IGlobalOptions IGlobalOptions_iface;
     LONG ref;
diff --git a/dlls/ole32/ole32.spec b/dlls/ole32/ole32.spec
index eab8664ae1e..58bdd22d682 100644
--- a/dlls/ole32/ole32.spec
+++ b/dlls/ole32/ole32.spec
@@ -66,8 +66,8 @@
 @ stdcall CoRegisterMallocSpy (ptr)
 @ stdcall CoRegisterMessageFilter(ptr ptr)
 @ stdcall CoRegisterPSClsid(ptr ptr)
-@ stub CoRegisterSurrogate
-@ stub CoRegisterSurrogateEx
+@ stdcall CoRegisterSurrogate(ptr)
+@ stdcall CoRegisterSurrogateEx(ptr ptr)
 @ stdcall CoReleaseMarshalData(ptr)
 @ stdcall CoReleaseServerProcess()
 @ stdcall CoResumeClassObjects()