diff --git a/src/util/postprocessing_shader_fx.cpp b/src/util/postprocessing_shader_fx.cpp
index 5fb4fb9e9..a42202b7a 100644
--- a/src/util/postprocessing_shader_fx.cpp
+++ b/src/util/postprocessing_shader_fx.cpp
@@ -326,8 +326,8 @@ bool PostProcessing::ReShadeFXShader::CreateModule(s32 buffer_width, s32 buffer_
   pp.add_macro_definition("__RESHADE__", "50901");
   pp.add_macro_definition("BUFFER_WIDTH", std::to_string(buffer_width)); // TODO: can we make these uniforms?
   pp.add_macro_definition("BUFFER_HEIGHT", std::to_string(buffer_height));
-  pp.add_macro_definition("BUFFER_RCP_WIDTH", fmt::format("({}.0 / BUFFER_WIDTH)", buffer_width));
-  pp.add_macro_definition("BUFFER_RCP_HEIGHT", fmt::format("({}.0 / BUFFER_HEIGHT)", buffer_height));
+  pp.add_macro_definition("BUFFER_RCP_WIDTH", std::to_string(1.0f / static_cast<float>(buffer_width)));
+  pp.add_macro_definition("BUFFER_RCP_HEIGHT", std::to_string(1.0f / static_cast<float>(buffer_height)));
 
   switch (GetRenderAPI())
   {