diff --git a/dlls/d3d9/buffer.c b/dlls/d3d9/buffer.c
index 07bdfa9320e..901557c288f 100644
--- a/dlls/d3d9/buffer.c
+++ b/dlls/d3d9/buffer.c
@@ -199,11 +199,9 @@ static HRESULT WINAPI d3d9_vertexbuffer_Lock(IDirect3DVertexBuffer9 *iface, UINT
 
     wined3d_box_set(&wined3d_box, offset, 0, offset + size, 1, 0, 1);
 
-    wined3d_mutex_lock();
     wined3d_resource = wined3d_buffer_get_resource(buffer->wined3d_buffer);
     hr = wined3d_resource_map(wined3d_resource, 0, &wined3d_map_desc, &wined3d_box,
             wined3dmapflags_from_d3dmapflags(flags, buffer->usage));
-    wined3d_mutex_unlock();
     *data = wined3d_map_desc.data;
 
     return hr;
@@ -215,9 +213,7 @@ static HRESULT WINAPI d3d9_vertexbuffer_Unlock(IDirect3DVertexBuffer9 *iface)
 
     TRACE("iface %p.\n", iface);
 
-    wined3d_mutex_lock();
     wined3d_resource_unmap(wined3d_buffer_get_resource(buffer->wined3d_buffer), 0);
-    wined3d_mutex_unlock();
 
     return D3D_OK;
 }
@@ -535,11 +531,9 @@ static HRESULT WINAPI d3d9_indexbuffer_Lock(IDirect3DIndexBuffer9 *iface,
 
     wined3d_box_set(&wined3d_box, offset, 0, offset + size, 1, 0, 1);
 
-    wined3d_mutex_lock();
     wined3d_resource = wined3d_buffer_get_resource(buffer->wined3d_buffer);
     hr = wined3d_resource_map(wined3d_resource, 0, &wined3d_map_desc, &wined3d_box,
             wined3dmapflags_from_d3dmapflags(flags, buffer->usage));
-    wined3d_mutex_unlock();
     *data = wined3d_map_desc.data;
 
     return hr;
@@ -551,9 +545,7 @@ static HRESULT WINAPI d3d9_indexbuffer_Unlock(IDirect3DIndexBuffer9 *iface)
 
     TRACE("iface %p.\n", iface);
 
-    wined3d_mutex_lock();
     wined3d_resource_unmap(wined3d_buffer_get_resource(buffer->wined3d_buffer), 0);
-    wined3d_mutex_unlock();
 
     return D3D_OK;
 }
diff --git a/dlls/d3d9/surface.c b/dlls/d3d9/surface.c
index d4738d2ca9f..2ff5134781e 100644
--- a/dlls/d3d9/surface.c
+++ b/dlls/d3d9/surface.c
@@ -246,10 +246,8 @@ static HRESULT WINAPI d3d9_surface_LockRect(IDirect3DSurface9 *iface,
     if (rect)
         wined3d_box_set(&box, rect->left, rect->top, rect->right, rect->bottom, 0, 1);
 
-    wined3d_mutex_lock();
     hr = wined3d_resource_map(wined3d_texture_get_resource(surface->wined3d_texture), surface->sub_resource_idx,
             &map_desc, rect ? &box : NULL, wined3dmapflags_from_d3dmapflags(flags, 0));
-    wined3d_mutex_unlock();
 
     if (SUCCEEDED(hr))
     {
diff --git a/dlls/d3d9/volume.c b/dlls/d3d9/volume.c
index 39caa8fb08e..e8091aec7a5 100644
--- a/dlls/d3d9/volume.c
+++ b/dlls/d3d9/volume.c
@@ -144,12 +144,10 @@ static HRESULT WINAPI d3d9_volume_LockBox(IDirect3DVolume9 *iface,
     TRACE("iface %p, locked_box %p, box %p, flags %#x.\n",
             iface, locked_box, box, flags);
 
-    wined3d_mutex_lock();
     if (FAILED(hr = wined3d_resource_map(wined3d_texture_get_resource(volume->wined3d_texture),
             volume->sub_resource_idx, &map_desc, (const struct wined3d_box *)box,
             wined3dmapflags_from_d3dmapflags(flags, 0))))
         map_desc.data = NULL;
-    wined3d_mutex_unlock();
 
     locked_box->RowPitch = map_desc.row_pitch;
     locked_box->SlicePitch = map_desc.slice_pitch;
@@ -167,9 +165,7 @@ static HRESULT WINAPI d3d9_volume_UnlockBox(IDirect3DVolume9 *iface)
 
     TRACE("iface %p.\n", iface);
 
-    wined3d_mutex_lock();
     hr = wined3d_resource_unmap(wined3d_texture_get_resource(volume->wined3d_texture), volume->sub_resource_idx);
-    wined3d_mutex_unlock();
 
     if (hr == WINEDDERR_NOTLOCKED)
         return D3DERR_INVALIDCALL;