diff --git a/dlls/d3d10core/d3d10core_private.h b/dlls/d3d10core/d3d10core_private.h
index 12af2826469..d3be62b1cc1 100644
--- a/dlls/d3d10core/d3d10core_private.h
+++ b/dlls/d3d10core/d3d10core_private.h
@@ -209,7 +209,7 @@ void shader_free_signature(struct wined3d_shader_signature *s) DECLSPEC_HIDDEN;
 /* ID3D10BlendState */
 struct d3d10_blend_state
 {
-    const struct ID3D10BlendStateVtbl *vtbl;
+    ID3D10BlendState ID3D10BlendState_iface;
     LONG refcount;
 };
 
diff --git a/dlls/d3d10core/device.c b/dlls/d3d10core/device.c
index 59a3b6083b9..bec59cee710 100644
--- a/dlls/d3d10core/device.c
+++ b/dlls/d3d10core/device.c
@@ -968,7 +968,7 @@ static HRESULT STDMETHODCALLTYPE d3d10_device_CreateBlendState(ID3D10Device *ifa
     }
 
     TRACE("Created blend state %p.\n", object);
-    *blend_state = (ID3D10BlendState *)object;
+    *blend_state = &object->ID3D10BlendState_iface;
 
     return S_OK;
 }
diff --git a/dlls/d3d10core/state.c b/dlls/d3d10core/state.c
index 2eaa652a3ce..5051f117fd8 100644
--- a/dlls/d3d10core/state.c
+++ b/dlls/d3d10core/state.c
@@ -24,6 +24,11 @@
 
 WINE_DEFAULT_DEBUG_CHANNEL(d3d10core);
 
+static inline struct d3d10_blend_state *impl_from_ID3D10BlendState(ID3D10BlendState *iface)
+{
+    return CONTAINING_RECORD(iface, struct d3d10_blend_state, ID3D10BlendState_iface);
+}
+
 /* IUnknown methods */
 
 static HRESULT STDMETHODCALLTYPE d3d10_blend_state_QueryInterface(ID3D10BlendState *iface,
@@ -48,7 +53,7 @@ static HRESULT STDMETHODCALLTYPE d3d10_blend_state_QueryInterface(ID3D10BlendSta
 
 static ULONG STDMETHODCALLTYPE d3d10_blend_state_AddRef(ID3D10BlendState *iface)
 {
-    struct d3d10_blend_state *This = (struct d3d10_blend_state *)iface;
+    struct d3d10_blend_state *This = impl_from_ID3D10BlendState(iface);
     ULONG refcount = InterlockedIncrement(&This->refcount);
 
     TRACE("%p increasing refcount to %u.\n", This, refcount);
@@ -58,7 +63,7 @@ static ULONG STDMETHODCALLTYPE d3d10_blend_state_AddRef(ID3D10BlendState *iface)
 
 static ULONG STDMETHODCALLTYPE d3d10_blend_state_Release(ID3D10BlendState *iface)
 {
-    struct d3d10_blend_state *This = (struct d3d10_blend_state *)iface;
+    struct d3d10_blend_state *This = impl_from_ID3D10BlendState(iface);
     ULONG refcount = InterlockedDecrement(&This->refcount);
 
     TRACE("%p decreasing refcount to %u.\n", This, refcount);
@@ -129,7 +134,7 @@ static const struct ID3D10BlendStateVtbl d3d10_blend_state_vtbl =
 
 HRESULT d3d10_blend_state_init(struct d3d10_blend_state *state)
 {
-    state->vtbl = &d3d10_blend_state_vtbl;
+    state->ID3D10BlendState_iface.lpVtbl = &d3d10_blend_state_vtbl;
     state->refcount = 1;
 
     return S_OK;