diff --git a/dlls/wined3d/stateblock.c b/dlls/wined3d/stateblock.c
index 24fd551adcc..1d522ad89b8 100644
--- a/dlls/wined3d/stateblock.c
+++ b/dlls/wined3d/stateblock.c
@@ -1546,6 +1546,15 @@ void CDECL wined3d_stateblock_set_material(struct wined3d_stateblock *stateblock
     stateblock->changed.material = TRUE;
 }
 
+void CDECL wined3d_stateblock_set_viewport(struct wined3d_stateblock *stateblock,
+        const struct wined3d_viewport *viewport)
+{
+    TRACE("stateblock %p, viewport %p.\n", stateblock, viewport);
+
+    stateblock->stateblock_state.viewport = *viewport;
+    stateblock->changed.viewport = TRUE;
+}
+
 static void init_default_render_states(DWORD rs[WINEHIGHEST_RENDER_STATE + 1], const struct wined3d_d3d_info *d3d_info)
 {
     union
diff --git a/dlls/wined3d/wined3d.spec b/dlls/wined3d/wined3d.spec
index 4f3cdf9b7b2..48e5ea954bc 100644
--- a/dlls/wined3d/wined3d.spec
+++ b/dlls/wined3d/wined3d.spec
@@ -277,6 +277,7 @@
 @ cdecl wined3d_stateblock_set_transform(ptr long ptr)
 @ cdecl wined3d_stateblock_set_vertex_declaration(ptr ptr)
 @ cdecl wined3d_stateblock_set_vertex_shader(ptr ptr)
+@ cdecl wined3d_stateblock_set_viewport(ptr ptr)
 @ cdecl wined3d_stateblock_set_vs_consts_b(ptr long long ptr)
 @ cdecl wined3d_stateblock_set_vs_consts_f(ptr long long ptr)
 @ cdecl wined3d_stateblock_set_vs_consts_i(ptr long long ptr)
diff --git a/include/wine/wined3d.h b/include/wine/wined3d.h
index 0b535475d0d..c311ded731e 100644
--- a/include/wine/wined3d.h
+++ b/include/wine/wined3d.h
@@ -2692,6 +2692,7 @@ void __cdecl wined3d_stateblock_set_transform(struct wined3d_stateblock *statebl
 void __cdecl wined3d_stateblock_set_vertex_declaration(struct wined3d_stateblock *stateblock,
         struct wined3d_vertex_declaration *declaration);
 void __cdecl wined3d_stateblock_set_vertex_shader(struct wined3d_stateblock *stateblock, struct wined3d_shader *shader);
+void __cdecl wined3d_stateblock_set_viewport(struct wined3d_stateblock *stateblock, const struct wined3d_viewport *viewport);
 HRESULT __cdecl wined3d_stateblock_set_vs_consts_b(struct wined3d_stateblock *stateblock,
         unsigned int start_idx, unsigned int count, const BOOL *constants);
 HRESULT __cdecl wined3d_stateblock_set_vs_consts_f(struct wined3d_stateblock *stateblock,