diff --git a/dlls/ddraw/light.c b/dlls/ddraw/light.c
index 93144d32cf2..aeb8390f82c 100644
--- a/dlls/ddraw/light.c
+++ b/dlls/ddraw/light.c
@@ -201,10 +201,12 @@ IDirect3DLightImpl_SetLight(IDirect3DLight *iface,
     light7->dvTheta        = lpLight->dvTheta;
     light7->dvPhi          = lpLight->dvPhi;
 
+    EnterCriticalSection(&ddraw_cs);
     memcpy(&This->light, lpLight, lpLight->dwSize);
     if ((This->light.dwFlags & D3DLIGHT_ACTIVE) != 0) {
         This->update(This);        
     }
+    LeaveCriticalSection(&ddraw_cs);
     return D3D_OK;
 }
 
@@ -230,7 +232,11 @@ IDirect3DLightImpl_GetLight(IDirect3DLight *iface,
         TRACE("  Returning light definition :\n");
 	dump_light(&This->light);
     }
+
+    EnterCriticalSection(&ddraw_cs);
     memcpy(lpLight, &This->light, lpLight->dwSize);
+    LeaveCriticalSection(&ddraw_cs);
+
     return DD_OK;
 }