diff --git a/dlls/ddraw/ddraw_private.h b/dlls/ddraw/ddraw_private.h
index ed4cdfce7ba..1ae10542484 100644
--- a/dlls/ddraw/ddraw_private.h
+++ b/dlls/ddraw/ddraw_private.h
@@ -535,6 +535,8 @@ struct d3d_vertex_buffer
     DWORD                fvf;
     DWORD                size;
     BOOL                 dynamic;
+
+    BOOL                 read_since_last_map;
 };
 
 HRESULT d3d_vertex_buffer_create(struct d3d_vertex_buffer **buffer, struct ddraw *ddraw,
diff --git a/dlls/ddraw/device.c b/dlls/ddraw/device.c
index 601c96e130e..8201d75f974 100644
--- a/dlls/ddraw/device.c
+++ b/dlls/ddraw/device.c
@@ -4113,6 +4113,10 @@ static HRESULT d3d_device7_DrawPrimitiveVB(IDirect3DDevice7 *iface, D3DPRIMITIVE
     /* Now draw the primitives */
     wined3d_device_set_primitive_type(device->wined3d_device, PrimitiveType);
     hr = wined3d_device_draw_primitive(device->wined3d_device, StartVertex, NumVertices);
+
+    if (SUCCEEDED(hr))
+        vb->read_since_last_map = TRUE;
+
     wined3d_mutex_unlock();
 
     return hr;
@@ -4236,6 +4240,9 @@ static HRESULT d3d_device7_DrawIndexedPrimitiveVB(IDirect3DDevice7 *iface,
     wined3d_device_set_primitive_type(This->wined3d_device, PrimitiveType);
     hr = wined3d_device_draw_indexed_primitive(This->wined3d_device, ib_pos / sizeof(WORD), IndexCount);
 
+    if (SUCCEEDED(hr))
+        vb->read_since_last_map = TRUE;
+
     wined3d_mutex_unlock();
 
     return hr;
diff --git a/dlls/ddraw/tests/ddraw4.c b/dlls/ddraw/tests/ddraw4.c
index a435b7a7c25..2e9c84516a8 100644
--- a/dlls/ddraw/tests/ddraw4.c
+++ b/dlls/ddraw/tests/ddraw4.c
@@ -2856,6 +2856,85 @@ static void test_coop_level_surf_create(void)
     IDirectDraw4_Release(ddraw);
 }
 
+static void test_vb_discard(void)
+{
+    static const struct vec4 quad[] =
+    {
+        {  0.0f, 480.0f, 0.0f, 1.0f},
+        {  0.0f,   0.0f, 0.0f, 1.0f},
+        {640.0f, 480.0f, 0.0f, 1.0f},
+        {640.0f,   0.0f, 0.0f, 1.0f},
+    };
+
+    IDirect3DDevice3 *device;
+    IDirect3D3 *d3d;
+    IDirect3DVertexBuffer *buffer;
+    HWND window;
+    HRESULT hr;
+    D3DVERTEXBUFFERDESC desc;
+    BYTE *data;
+    static const unsigned int vbsize = 16;
+    unsigned int i;
+
+    window = CreateWindowA("static", "ddraw_test", WS_OVERLAPPEDWINDOW,
+            0, 0, 640, 480, 0, 0, 0, 0);
+
+    if (!(device = create_device(window, DDSCL_NORMAL)))
+    {
+        skip("Failed to create D3D device, skipping test.\n");
+        DestroyWindow(window);
+        return;
+    }
+
+    hr = IDirect3DDevice3_GetDirect3D(device, &d3d);
+    ok(SUCCEEDED(hr), "Failed to get d3d interface, hr %#x.\n", hr);
+
+    memset(&desc, 0, sizeof(desc));
+    desc.dwSize = sizeof(desc);
+    desc.dwCaps = D3DVBCAPS_WRITEONLY;
+    desc.dwFVF = D3DFVF_XYZRHW;
+    desc.dwNumVertices = vbsize;
+    hr = IDirect3D3_CreateVertexBuffer(d3d, &desc, &buffer, 0, NULL);
+    ok(SUCCEEDED(hr), "Failed to create vertex buffer, hr %#x.\n", hr);
+
+    hr = IDirect3DVertexBuffer_Lock(buffer, DDLOCK_DISCARDCONTENTS, (void **)&data, NULL);
+    ok(SUCCEEDED(hr), "Failed to lock vertex buffer, hr %#x.\n", hr);
+    memcpy(data, quad, sizeof(quad));
+    hr = IDirect3DVertexBuffer_Unlock(buffer);
+    ok(SUCCEEDED(hr), "Failed to unlock vertex buffer, hr %#x.\n", hr);
+
+    hr = IDirect3DDevice3_BeginScene(device);
+    ok(SUCCEEDED(hr), "Failed to begin scene, hr %#x.\n", hr);
+    hr = IDirect3DDevice3_DrawPrimitiveVB(device, D3DPT_TRIANGLESTRIP, buffer, 0, 4, 0);
+    ok(SUCCEEDED(hr), "Failed to draw, hr %#x.\n", hr);
+    hr = IDirect3DDevice3_EndScene(device);
+    ok(SUCCEEDED(hr), "Failed to end scene, hr %#x.\n", hr);
+
+    hr = IDirect3DVertexBuffer_Lock(buffer, DDLOCK_DISCARDCONTENTS, (void **)&data, NULL);
+    ok(SUCCEEDED(hr), "Failed to lock vertex buffer, hr %#x.\n", hr);
+    memset(data, 0xaa, sizeof(struct vec4) * vbsize);
+    hr = IDirect3DVertexBuffer_Unlock(buffer);
+    ok(SUCCEEDED(hr), "Failed to unlock vertex buffer, hr %#x.\n", hr);
+
+    hr = IDirect3DVertexBuffer_Lock(buffer, DDLOCK_DISCARDCONTENTS, (void **)&data, NULL);
+    ok(SUCCEEDED(hr), "Failed to lock vertex buffer, hr %#x.\n", hr);
+    for (i = 0; i < sizeof(struct vec4) * vbsize; i++)
+    {
+        if (data[i] != 0xaa)
+        {
+            ok(FALSE, "Vertex buffer data byte %u is 0x%02x, expected 0xaa\n", i, data[i]);
+            break;
+        }
+    }
+    hr = IDirect3DVertexBuffer_Unlock(buffer);
+    ok(SUCCEEDED(hr), "Failed to unlock vertex buffer, hr %#x.\n", hr);
+
+    IDirect3DVertexBuffer_Release(buffer);
+    IDirect3D3_Release(d3d);
+    IDirect3DDevice3_Release(device);
+    DestroyWindow(window);
+}
+
 START_TEST(ddraw4)
 {
     test_process_vertices();
@@ -2879,4 +2958,5 @@ START_TEST(ddraw4)
     test_coop_level_mode_set_multi();
     test_initialize();
     test_coop_level_surf_create();
+    test_vb_discard();
 }
diff --git a/dlls/ddraw/tests/ddraw7.c b/dlls/ddraw/tests/ddraw7.c
index 7985b066663..2b7e0751f23 100644
--- a/dlls/ddraw/tests/ddraw7.c
+++ b/dlls/ddraw/tests/ddraw7.c
@@ -2665,6 +2665,85 @@ static void test_coop_level_surf_create(void)
     IDirectDraw7_Release(ddraw);
 }
 
+static void test_vb_discard(void)
+{
+    static const struct vec4 quad[] =
+    {
+        {  0.0f, 480.0f, 0.0f, 1.0f},
+        {  0.0f,   0.0f, 0.0f, 1.0f},
+        {640.0f, 480.0f, 0.0f, 1.0f},
+        {640.0f,   0.0f, 0.0f, 1.0f},
+    };
+
+    IDirect3DDevice7 *device;
+    IDirect3D7 *d3d;
+    IDirect3DVertexBuffer7 *buffer;
+    HWND window;
+    HRESULT hr;
+    D3DVERTEXBUFFERDESC desc;
+    BYTE *data;
+    static const unsigned int vbsize = 16;
+    unsigned int i;
+
+    window = CreateWindowA("static", "ddraw_test", WS_OVERLAPPEDWINDOW,
+            0, 0, 640, 480, 0, 0, 0, 0);
+
+    if (!(device = create_device(window, DDSCL_NORMAL)))
+    {
+        skip("Failed to create D3D device, skipping test.\n");
+        DestroyWindow(window);
+        return;
+    }
+
+    hr = IDirect3DDevice7_GetDirect3D(device, &d3d);
+    ok(SUCCEEDED(hr), "Failed to get d3d interface, hr %#x.\n", hr);
+
+    memset(&desc, 0, sizeof(desc));
+    desc.dwSize = sizeof(desc);
+    desc.dwCaps = D3DVBCAPS_WRITEONLY;
+    desc.dwFVF = D3DFVF_XYZRHW;
+    desc.dwNumVertices = vbsize;
+    hr = IDirect3D7_CreateVertexBuffer(d3d, &desc, &buffer, 0);
+    ok(SUCCEEDED(hr), "Failed to create vertex buffer, hr %#x.\n", hr);
+
+    hr = IDirect3DVertexBuffer7_Lock(buffer, DDLOCK_DISCARDCONTENTS, (void **)&data, NULL);
+    ok(SUCCEEDED(hr), "Failed to lock vertex buffer, hr %#x.\n", hr);
+    memcpy(data, quad, sizeof(quad));
+    hr = IDirect3DVertexBuffer7_Unlock(buffer);
+    ok(SUCCEEDED(hr), "Failed to unlock vertex buffer, hr %#x.\n", hr);
+
+    hr = IDirect3DDevice7_BeginScene(device);
+    ok(SUCCEEDED(hr), "Failed to begin scene, hr %#x.\n", hr);
+    hr = IDirect3DDevice7_DrawPrimitiveVB(device, D3DPT_TRIANGLESTRIP, buffer, 0, 4, 0);
+    ok(SUCCEEDED(hr), "Failed to draw, hr %#x.\n", hr);
+    hr = IDirect3DDevice7_EndScene(device);
+    ok(SUCCEEDED(hr), "Failed to end scene, hr %#x.\n", hr);
+
+    hr = IDirect3DVertexBuffer7_Lock(buffer, DDLOCK_DISCARDCONTENTS, (void **)&data, NULL);
+    ok(SUCCEEDED(hr), "Failed to lock vertex buffer, hr %#x.\n", hr);
+    memset(data, 0xaa, sizeof(struct vec4) * vbsize);
+    hr = IDirect3DVertexBuffer7_Unlock(buffer);
+    ok(SUCCEEDED(hr), "Failed to unlock vertex buffer, hr %#x.\n", hr);
+
+    hr = IDirect3DVertexBuffer7_Lock(buffer, DDLOCK_DISCARDCONTENTS, (void **)&data, NULL);
+    ok(SUCCEEDED(hr), "Failed to lock vertex buffer, hr %#x.\n", hr);
+    for (i = 0; i < sizeof(struct vec4) * vbsize; i++)
+    {
+        if (data[i] != 0xaa)
+        {
+            ok(FALSE, "Vertex buffer data byte %u is 0x%02x, expected 0xaa\n", i, data[i]);
+            break;
+        }
+    }
+    hr = IDirect3DVertexBuffer7_Unlock(buffer);
+    ok(SUCCEEDED(hr), "Failed to unlock vertex buffer, hr %#x.\n", hr);
+
+    IDirect3DVertexBuffer7_Release(buffer);
+    IDirect3D7_Release(d3d);
+    IDirect3DDevice7_Release(device);
+    DestroyWindow(window);
+}
+
 START_TEST(ddraw7)
 {
     HMODULE module = GetModuleHandleA("ddraw.dll");
@@ -2695,4 +2774,5 @@ START_TEST(ddraw7)
     test_coop_level_mode_set_multi();
     test_initialize();
     test_coop_level_surf_create();
+    test_vb_discard();
 }
diff --git a/dlls/ddraw/vertexbuffer.c b/dlls/ddraw/vertexbuffer.c
index 1b5d7af86d2..5acd2e618a4 100644
--- a/dlls/ddraw/vertexbuffer.c
+++ b/dlls/ddraw/vertexbuffer.c
@@ -245,7 +245,7 @@ static HRESULT WINAPI d3d_vertex_buffer7_Lock(IDirect3DVertexBuffer7 *iface,
         wined3d_flags |= WINED3D_MAP_READONLY;
     if (flags & DDLOCK_NOOVERWRITE)
         wined3d_flags |= WINED3D_MAP_NOOVERWRITE;
-    if (flags & DDLOCK_DISCARDCONTENTS)
+    if (flags & DDLOCK_DISCARDCONTENTS && buffer->read_since_last_map)
     {
         wined3d_flags |= WINED3D_MAP_DISCARD;
 
@@ -278,6 +278,10 @@ static HRESULT WINAPI d3d_vertex_buffer7_Lock(IDirect3DVertexBuffer7 *iface,
     }
 
     hr = wined3d_buffer_map(buffer->wineD3DVertexBuffer, 0, 0, (BYTE **)data, wined3d_flags);
+
+    if (SUCCEEDED(hr))
+        buffer->read_since_last_map = FALSE;
+
     wined3d_mutex_unlock();
 
     return hr;