diff --git a/winbuild/build_prepare.py b/winbuild/build_prepare.py
index 0abf624b7e2..b87b828bfbc 100644
--- a/winbuild/build_prepare.py
+++ b/winbuild/build_prepare.py
@@ -255,7 +255,7 @@ def cmd_msbuild(
             ),
         ],
         "headers": [r"png*.h"],
-        "libs": [rf"libpng{V['LIBPNG_XY']}.lib"],
+        "libs": [f"libpng{V['LIBPNG_XY']}.lib"],
     },
     "brotli": {
         "url": f"https://github.com/google/brotli/archive/refs/tags/v{V['BROTLI']}.tar.gz",