diff --git a/tests/pngstest b/tests/pngstest
index d73843c6a..0400b073f 100755
--- a/tests/pngstest
+++ b/tests/pngstest
@@ -17,8 +17,7 @@ gamma="$1"
 shift
 alpha="$1"
 shift
-exec ./pngstest --tmpfile "${gamma}-${alpha}-" --log ${1+"$@"}
-(
+exec ./pngstest --tmpfile "${gamma}-${alpha}-" --log ${1+"$@"} `
    for f in "${srcdir}/contrib/testpngs/"*.png
    do
       g=
@@ -50,4 +49,4 @@ exec ./pngstest --tmpfile "${gamma}-${alpha}-" --log ${1+"$@"}
             test "$alpha" = "opaque" -o "$alpha" = "none" && echo "$g";;
       esac
    done
-)
+`