diff --git a/tests/shader_runner.c b/tests/shader_runner.c
index d68d7f18..910e6ecd 100644
--- a/tests/shader_runner.c
+++ b/tests/shader_runner.c
@@ -293,7 +293,7 @@ static void parse_test_directive(struct shader_runner *runner, const char *line)
     }
     else if (match_string(line, "probe all rgba", &line))
     {
-        static const RECT rect = {0, 0, 640, 480};
+        static const RECT rect = {0, 0, RENDER_TARGET_WIDTH, RENDER_TARGET_HEIGHT};
         unsigned int ulps;
         struct vec4 v;
         int ret;
diff --git a/tests/shader_runner.h b/tests/shader_runner.h
index 84c17016..26fa2367 100644
--- a/tests/shader_runner.h
+++ b/tests/shader_runner.h
@@ -24,6 +24,9 @@
 #include "vkd3d_common.h"
 #include "utils.h"
 
+#define RENDER_TARGET_WIDTH 640
+#define RENDER_TARGET_HEIGHT 480
+
 enum shader_model
 {
     SHADER_MODEL_2_0,
diff --git a/tests/shader_runner_d3d11.c b/tests/shader_runner_d3d11.c
index 0a8e0efe..884d86af 100644
--- a/tests/shader_runner_d3d11.c
+++ b/tests/shader_runner_d3d11.c
@@ -241,8 +241,8 @@ static IDXGISwapChain *create_swapchain(ID3D11Device *device, HWND window)
     ok(hr == S_OK, "Failed to get factory, hr %#lx.\n", hr);
     IDXGIAdapter_Release(adapter);
 
-    dxgi_desc.BufferDesc.Width = 640;
-    dxgi_desc.BufferDesc.Height = 480;
+    dxgi_desc.BufferDesc.Width = RENDER_TARGET_WIDTH;
+    dxgi_desc.BufferDesc.Height = RENDER_TARGET_HEIGHT;
     dxgi_desc.BufferDesc.RefreshRate.Numerator = 60;
     dxgi_desc.BufferDesc.RefreshRate.Denominator = 1;
     dxgi_desc.BufferDesc.Format = DXGI_FORMAT_R8G8B8A8_UNORM;
@@ -268,8 +268,8 @@ static BOOL init_test_context(struct d3d11_shader_runner *runner)
 {
     const D3D11_TEXTURE2D_DESC texture_desc =
     {
-        .Width = 640,
-        .Height = 480,
+        .Width = RENDER_TARGET_WIDTH,
+        .Height = RENDER_TARGET_HEIGHT,
         .MipLevels = 1,
         .ArraySize = 1,
         .Format = DXGI_FORMAT_R32G32B32A32_FLOAT,
@@ -290,8 +290,8 @@ static BOOL init_test_context(struct d3d11_shader_runner *runner)
         return FALSE;
     }
 
-    rt_width = 640;
-    rt_height = 480;
+    rt_width = RENDER_TARGET_WIDTH;
+    rt_height = RENDER_TARGET_HEIGHT;
     SetRect(&rect, 0, 0, rt_width, rt_height);
     AdjustWindowRect(&rect, WS_OVERLAPPEDWINDOW, FALSE);
     runner->window = CreateWindowA("static", "d3dcompiler_test", WS_OVERLAPPEDWINDOW,
diff --git a/tests/shader_runner_d3d12.c b/tests/shader_runner_d3d12.c
index a6db29ff..4f077b38 100644
--- a/tests/shader_runner_d3d12.c
+++ b/tests/shader_runner_d3d12.c
@@ -269,8 +269,8 @@ void run_shader_tests_d3d12(int argc, char **argv)
 {
     static const struct test_context_desc desc =
     {
-        .rt_width = 640,
-        .rt_height = 480,
+        .rt_width = RENDER_TARGET_WIDTH,
+        .rt_height = RENDER_TARGET_HEIGHT,
         .no_root_signature = true,
         .rt_format = DXGI_FORMAT_R32G32B32A32_FLOAT,
     };