diff --git a/tests/build-hook.hook.sh b/tests/build-hook.hook.sh
index 18eba283e1..83fa3bf787 100755
--- a/tests/build-hook.hook.sh
+++ b/tests/build-hook.hook.sh
@@ -6,11 +6,11 @@ drv=$4
 
 echo "HOOK for $drv" >&2
 
-outPath=$(sed 's/Derive(\[("out",\"\([^\"]*\)\".*/\1/' $drv)
+outPath=`sed 's/Derive(\[("out",\"\([^\"]*\)\".*/\1/' $drv`
 
 echo "output path is $outPath" >&2
 
-if $(echo $outPath | grep -q input-1); then
+if `echo $outPath | grep -q input-1`; then
     echo "# accept" >&2
     read x
     echo "got $x"