--- a/src/img2pdf_test.py	2023-01-22 18:36:32.208977359 +0100
+++ b/src/img2pdf_test.py	2023-01-22 18:39:52.918531386 +0100
@@ -345,7 +345,7 @@
             stderr=subprocess.PIPE,
         ).stderr
         assert psnr != b"0"
-        psnr = float(psnr.strip(b"0"))
+        psnr = float(psnr.split()[0])
         assert psnr != 0  # or otherwise we would use the exact variant
         assert psnr > 50
 
@@ -501,7 +501,7 @@
                 stderr=subprocess.PIPE,
             ).stderr
         assert psnr != b"0"
-        psnr = float(psnr.strip(b"0"))
+        psnr = float(psnr.split()[0])
         assert psnr != 0  # or otherwise we would use the exact variant
         assert psnr > 50
     (tmpdir / "images-000.png").unlink()