diff --git a/configure.ac b/configure.ac
index abd94b51..7b72d3ed 100644
--- a/configure.ac
+++ b/configure.ac
@@ -44,6 +44,7 @@ AS_IF([test "x${GCC}" = "xyes"],
       [VKD3D_CFLAGS="-Wall -pipe"
       VKD3D_CHECK_CFLAGS([-std=c99])
       VKD3D_CHECK_CFLAGS([-Wdeclaration-after-statement])
+      VKD3D_CHECK_CFLAGS([-Wimplicit-fallthrough])
       VKD3D_CHECK_CFLAGS([-Wmissing-prototypes])
       VKD3D_CHECK_CFLAGS([-Wunused-but-set-parameter])
       VKD3D_CHECK_CFLAGS([-Wvla])
diff --git a/libs/vkd3d/utils.c b/libs/vkd3d/utils.c
index 0329499f..6a910a79 100644
--- a/libs/vkd3d/utils.c
+++ b/libs/vkd3d/utils.c
@@ -702,10 +702,12 @@ HRESULT hresult_from_vk_result(VkResult vr)
             return S_OK;
         case VK_ERROR_OUT_OF_DEVICE_MEMORY:
             WARN("Out of device memory.\n");
+            /* fall-through */
         case VK_ERROR_OUT_OF_HOST_MEMORY:
             return E_OUTOFMEMORY;
         default:
             FIXME("Unhandled VkResult %d.\n", vr);
+            /* fall-through */
         case VK_ERROR_DEVICE_LOST:
         case VK_ERROR_EXTENSION_NOT_PRESENT:
             return E_FAIL;