diff --git a/dlls/quartz/Makefile.in b/dlls/quartz/Makefile.in
index 858b9578792..ec29ef53c6b 100644
--- a/dlls/quartz/Makefile.in
+++ b/dlls/quartz/Makefile.in
@@ -15,6 +15,7 @@ C_SRCS = \
 	filtermapper.c \
 	main.c \
 	memallocator.c \
+	passthrough.c \
 	regsvr.c \
 	systemclock.c \
 	video.c \
diff --git a/dlls/quartz/main.c b/dlls/quartz/main.c
index 284f2cacaea..89c7fe9bb15 100644
--- a/dlls/quartz/main.c
+++ b/dlls/quartz/main.c
@@ -36,11 +36,6 @@ BOOL WINAPI DllMain(HINSTANCE instance, DWORD reason, void *reserved)
     return QUARTZ_DllMain(instance, reason, reserved);
 }
 
-static HRESULT seeking_passthrough_create(IUnknown *outer, IUnknown **out)
-{
-    return PosPassThru_Construct(outer, (void **)out);
-}
-
 /******************************************************************************
  * DirectShow ClassFactory
  */
diff --git a/dlls/quartz/passthrough.c b/dlls/quartz/passthrough.c
new file mode 100644
index 00000000000..2f8fe9dc370
--- /dev/null
+++ b/dlls/quartz/passthrough.c
@@ -0,0 +1,112 @@
+/*
+ * Seeking passthrough object
+ *
+ * Copyright 2020 Zebediah Figura for CodeWeavers
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2.1 of the License, or (at your option) any later version.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301, USA
+ */
+
+#include "quartz_private.h"
+
+WINE_DEFAULT_DEBUG_CHANNEL(quartz);
+
+struct seeking_passthrough
+{
+    struct strmbase_passthrough passthrough;
+
+    IUnknown IUnknown_inner;
+    IUnknown *outer_unk;
+    LONG refcount;
+};
+
+static struct seeking_passthrough *impl_from_IUnknown(IUnknown *iface)
+{
+    return CONTAINING_RECORD(iface, struct seeking_passthrough, IUnknown_inner);
+}
+
+static HRESULT WINAPI seeking_passthrough_QueryInterface(IUnknown *iface, REFIID iid, void **out)
+{
+    struct seeking_passthrough *passthrough = impl_from_IUnknown(iface);
+
+    TRACE("passthrough %p, iid %s, out %p.\n", passthrough, debugstr_guid(iid), out);
+
+    if (IsEqualGUID(iid, &IID_IUnknown))
+        *out = iface;
+    else if (IsEqualGUID(iid, &IID_IMediaPosition))
+        *out = &passthrough->passthrough.IMediaPosition_iface;
+    else if (IsEqualGUID(iid, &IID_IMediaSeeking))
+        *out = &passthrough->passthrough.IMediaSeeking_iface;
+    else if (IsEqualGUID(iid, &IID_ISeekingPassThru))
+        *out = &passthrough->passthrough.ISeekingPassThru_iface;
+    else
+    {
+        *out = NULL;
+        WARN("%s not implemented, returning E_NOINTERFACE.\n", debugstr_guid(iid));
+        return E_NOINTERFACE;
+    }
+
+    IUnknown_AddRef((IUnknown *)*out);
+    return S_OK;
+}
+
+static ULONG WINAPI seeking_passthrough_AddRef(IUnknown *iface)
+{
+    struct seeking_passthrough *passthrough = impl_from_IUnknown(iface);
+    ULONG refcount = InterlockedIncrement(&passthrough->refcount);
+
+    TRACE("%p increasing refcount to %u.\n", passthrough, refcount);
+    return refcount;
+}
+
+static ULONG WINAPI seeking_passthrough_Release(IUnknown *iface)
+{
+    struct seeking_passthrough *passthrough = impl_from_IUnknown(iface);
+    ULONG refcount = InterlockedDecrement(&passthrough->refcount);
+
+    TRACE("%p decreasing refcount to %u.\n", passthrough, refcount);
+    if (!refcount)
+    {
+        strmbase_passthrough_cleanup(&passthrough->passthrough);
+        free(passthrough);
+    }
+    return refcount;
+}
+
+static const IUnknownVtbl seeking_passthrough_vtbl =
+{
+    seeking_passthrough_QueryInterface,
+    seeking_passthrough_AddRef,
+    seeking_passthrough_Release,
+};
+
+HRESULT seeking_passthrough_create(IUnknown *outer, IUnknown **out)
+{
+    struct seeking_passthrough *object;
+
+    TRACE("outer %p, out %p.\n", outer, out);
+
+    if (!(object = calloc(1, sizeof(*object))))
+        return E_OUTOFMEMORY;
+
+    object->IUnknown_inner.lpVtbl = &seeking_passthrough_vtbl;
+    object->outer_unk = outer ? outer : &object->IUnknown_inner;
+    object->refcount = 1;
+
+    strmbase_passthrough_init(&object->passthrough, object->outer_unk);
+
+    TRACE("Created seeking passthrough %p.\n", object);
+    *out = &object->IUnknown_inner;
+    return S_OK;
+}
diff --git a/dlls/quartz/quartz_private.h b/dlls/quartz/quartz_private.h
index 3332c27d21a..55385379085 100644
--- a/dlls/quartz/quartz_private.h
+++ b/dlls/quartz/quartz_private.h
@@ -69,6 +69,7 @@ HRESULT filter_graph_no_thread_create(IUnknown *outer, IUnknown **out) DECLSPEC_
 HRESULT filter_mapper_create(IUnknown *outer, IUnknown **out) DECLSPEC_HIDDEN;
 HRESULT mem_allocator_create(IUnknown *outer, IUnknown **out) DECLSPEC_HIDDEN;
 HRESULT system_clock_create(IUnknown *outer, IUnknown **out) DECLSPEC_HIDDEN;
+HRESULT seeking_passthrough_create(IUnknown *outer, IUnknown **out) DECLSPEC_HIDDEN;
 HRESULT video_renderer_create(IUnknown *outer, IUnknown **out) DECLSPEC_HIDDEN;
 HRESULT video_renderer_default_create(IUnknown *outer, IUnknown **out) DECLSPEC_HIDDEN;
 HRESULT vmr7_create(IUnknown *outer, IUnknown **out) DECLSPEC_HIDDEN;
diff --git a/dlls/strmbase/pospass.c b/dlls/strmbase/pospass.c
index 3b4560d35eb..b9e6f23a974 100644
--- a/dlls/strmbase/pospass.c
+++ b/dlls/strmbase/pospass.c
@@ -764,92 +764,3 @@ void strmbase_passthrough_eos(struct strmbase_passthrough *passthrough)
         passthrough->timevalid = FALSE;
     LeaveCriticalSection(&passthrough->time_cs);
 }
-
-struct seeking_passthrough
-{
-    struct strmbase_passthrough passthrough;
-
-    IUnknown IUnknown_inner;
-    IUnknown *outer_unk;
-    LONG refcount;
-};
-
-static struct seeking_passthrough *impl_from_IUnknown(IUnknown *iface)
-{
-    return CONTAINING_RECORD(iface, struct seeking_passthrough, IUnknown_inner);
-}
-
-static HRESULT WINAPI seeking_passthrough_QueryInterface(IUnknown *iface, REFIID iid, void **out)
-{
-    struct seeking_passthrough *passthrough = impl_from_IUnknown(iface);
-
-    TRACE("passthrough %p, iid %s, out %p.\n", passthrough, debugstr_guid(iid), out);
-
-    if (IsEqualGUID(iid, &IID_IUnknown))
-        *out = iface;
-    else if (IsEqualGUID(iid, &IID_IMediaPosition))
-        *out = &passthrough->passthrough.IMediaPosition_iface;
-    else if (IsEqualGUID(iid, &IID_IMediaSeeking))
-        *out = &passthrough->passthrough.IMediaSeeking_iface;
-    else if (IsEqualGUID(iid, &IID_ISeekingPassThru))
-        *out = &passthrough->passthrough.ISeekingPassThru_iface;
-    else
-    {
-        *out = NULL;
-        WARN("%s not implemented, returning E_NOINTERFACE.\n", debugstr_guid(iid));
-        return E_NOINTERFACE;
-    }
-
-    IUnknown_AddRef((IUnknown *)*out);
-    return S_OK;
-}
-
-static ULONG WINAPI seeking_passthrough_AddRef(IUnknown *iface)
-{
-    struct seeking_passthrough *passthrough = impl_from_IUnknown(iface);
-    ULONG refcount = InterlockedIncrement(&passthrough->refcount);
-
-    TRACE("%p increasing refcount to %u.\n", passthrough, refcount);
-    return refcount;
-}
-
-static ULONG WINAPI seeking_passthrough_Release(IUnknown *iface)
-{
-    struct seeking_passthrough *passthrough = impl_from_IUnknown(iface);
-    ULONG refcount = InterlockedDecrement(&passthrough->refcount);
-
-    TRACE("%p decreasing refcount to %u.\n", passthrough, refcount);
-    if (!refcount)
-    {
-        strmbase_passthrough_cleanup(&passthrough->passthrough);
-        heap_free(passthrough);
-    }
-    return refcount;
-}
-
-static const IUnknownVtbl seeking_passthrough_vtbl =
-{
-    seeking_passthrough_QueryInterface,
-    seeking_passthrough_AddRef,
-    seeking_passthrough_Release,
-};
-
-HRESULT WINAPI PosPassThru_Construct(IUnknown *outer, void **out)
-{
-    struct seeking_passthrough *object;
-
-    TRACE("outer %p, out %p.\n", outer, out);
-
-    if (!(object = heap_alloc_zero(sizeof(*object))))
-        return E_OUTOFMEMORY;
-
-    object->IUnknown_inner.lpVtbl = &seeking_passthrough_vtbl;
-    object->outer_unk = outer ? outer : &object->IUnknown_inner;
-    object->refcount = 1;
-
-    strmbase_passthrough_init(&object->passthrough, object->outer_unk);
-
-    TRACE("Created seeking passthrough %p.\n", object);
-    *out = &object->IUnknown_inner;
-    return S_OK;
-}
diff --git a/include/wine/strmbase.h b/include/wine/strmbase.h
index 6d620c79337..732ba1be269 100644
--- a/include/wine/strmbase.h
+++ b/include/wine/strmbase.h
@@ -204,8 +204,6 @@ HRESULT WINAPI SourceSeekingImpl_SetRate(IMediaSeeking * iface, double dRate);
 HRESULT WINAPI SourceSeekingImpl_GetRate(IMediaSeeking * iface, double * dRate);
 HRESULT WINAPI SourceSeekingImpl_GetPreroll(IMediaSeeking * iface, LONGLONG * pPreroll);
 
-HRESULT WINAPI PosPassThru_Construct(IUnknown* pUnkOuter, LPVOID *ppPassThru);
-
 /* Output Queue */
 typedef struct tagOutputQueue {
     CRITICAL_SECTION csQueue;