diff --git a/tests/functional/derivation-instantiate.sh b/tests/functional/derivation-instantiate.sh
index fea0030c5..b46b177bc 100755
--- a/tests/functional/derivation-instantiate.sh
+++ b/tests/functional/derivation-instantiate.sh
@@ -7,38 +7,38 @@ TODO_NixOS
 clearStore
 
 drvPath=$(nix derivation instantiate --no-link --file simple.nix)
-test -f $drvPath
-nix-store --delete $drvPath
-! test -f $drvPath
+test -f "$drvPath"
+nix-store --delete "$drvPath"
+if test -f "$drvPath"; then false; fi
 
 drvPath=$(nix derivation instantiate --file simple.nix)
-test -f $drvPath
+test -f "$drvPath"
 test -e drv
-nix-store --gc --print-roots | grep $drvPath
-nix-store --gc --print-live | grep $drvPath
-! nix-store --delete $drvPath
-test -f $drvPath
-[ "$(nix-store -q --roots $drvPath)" = "$(realpath --no-symlinks drv) -> $drvPath" ]
+nix-store --gc --print-roots | grep "$drvPath"
+nix-store --gc --print-live | grep "$drvPath"
+if nix-store --delete "$drvPath"; then false; fi
+test -f "$drvPath"
+[ "$(nix-store -q --roots "$drvPath")" = "$(realpath --no-symlinks drv) -> $drvPath" ]
 rm drv
-nix-store --delete $drvPath
-! test -f $drvPath
+nix-store --delete "$drvPath"
+if test -f "$drvPath"; then false; fi
 
 drvPath=$(nix derivation instantiate --out-link foobar --file simple.nix)
 test -e foobar
-[ "$(nix-store -q --roots $drvPath)" = "$(realpath --no-symlinks foobar) -> $drvPath" ]
+[ "$(nix-store -q --roots "$drvPath")" = "$(realpath --no-symlinks foobar) -> $drvPath" ]
 rm foobar
-nix-store --delete $drvPath
+nix-store --delete "$drvPath"
 
 drvPathJson=$(nix derivation instantiate --json --no-link --file simple.nix)
-[ "$drvPathJson" = '{"'"$drvPath"'":{}}' ]
-nix-store --delete $drvPath
+[ "$drvPathJson" = "{\"$drvPath\":{}}" ]
+nix-store --delete "$drvPath"
 
-drvPaths=($(nix derivation instantiate --json --out-link multidrv --file check.nix | jq 'keys|.[]' -r))
+mapfile -t drvPaths < <(nix derivation instantiate --json --out-link multidrv --file check.nix | jq 'keys|.[]' -r)
 roots=(./multidrv*)
 [ "${#roots[@]}" -gt 1 ]
 [ "${#roots[@]}" -eq "${#drvPaths[@]}" ]
-rootedPaths=($(readlink "${roots[@]}"))
+mapfile -t rootedPaths < <(readlink "${roots[@]}")
 [ "${rootedPaths[*]}" = "${drvPaths[*]}" ]
-rm multidrv*
+rm -f multidrv*
 
 nix-collect-garbage