diff --git a/maintainers/flake-module.nix b/maintainers/flake-module.nix
index 3bf41bc14..43c84d5ae 100644
--- a/maintainers/flake-module.nix
+++ b/maintainers/flake-module.nix
@@ -106,7 +106,6 @@
             enable = true;
             excludes = [
               # We haven't linted these files yet
-              ''^tests/functional/impure-derivations\.sh$''
               ''^tests/functional/impure-eval\.sh$''
               ''^tests/functional/install-darwin\.sh$''
               ''^tests/functional/legacy-ssh-store\.sh$''
diff --git a/tests/functional/impure-derivations.sh b/tests/functional/impure-derivations.sh
index 9e483d376..e0b7c3eea 100755
--- a/tests/functional/impure-derivations.sh
+++ b/tests/functional/impure-derivations.sh
@@ -12,62 +12,62 @@ restartDaemon
 clearStoreIfPossible
 
 # Basic test of impure derivations: building one a second time should not use the previous result.
-printf 0 > $TEST_ROOT/counter
+printf 0 > "$TEST_ROOT"/counter
 
 # `nix derivation add` with impure derivations work
 drvPath=$(nix-instantiate ./impure-derivations.nix -A impure)
-nix derivation show $drvPath | jq .[] > $TEST_HOME/impure-drv.json
-drvPath2=$(nix derivation add < $TEST_HOME/impure-drv.json)
+nix derivation show "$drvPath" | jq .[] > "$TEST_HOME"/impure-drv.json
+drvPath2=$(nix derivation add < "$TEST_HOME"/impure-drv.json)
 [[ "$drvPath" = "$drvPath2" ]]
 
 # But only with the experimental feature!
-expectStderr 1 nix derivation add < $TEST_HOME/impure-drv.json --experimental-features nix-command | grepQuiet "experimental Nix feature 'impure-derivations' is disabled"
+expectStderr 1 nix derivation add < "$TEST_HOME"/impure-drv.json --experimental-features nix-command | grepQuiet "experimental Nix feature 'impure-derivations' is disabled"
 
 nix build --dry-run --json --file ./impure-derivations.nix impure.all
 json=$(nix build -L --no-link --json --file ./impure-derivations.nix impure.all)
-path1=$(echo $json | jq -r .[].outputs.out)
-path1_stuff=$(echo $json | jq -r .[].outputs.stuff)
-[[ $(< $path1/n) = 0 ]]
-[[ $(< $path1_stuff/bla) = 0 ]]
+path1=$(echo "$json" | jq -r .[].outputs.out)
+path1_stuff=$(echo "$json" | jq -r .[].outputs.stuff)
+[[ $(< "$path1"/n) = 0 ]]
+[[ $(< "$path1_stuff"/bla) = 0 ]]
 
-[[ $(nix path-info --json $path1 | jq .[].ca) =~ fixed:r:sha256: ]]
+[[ $(nix path-info --json "$path1" | jq .[].ca) =~ fixed:r:sha256: ]]
 
 path2=$(nix build -L --no-link --json --file ./impure-derivations.nix impure | jq -r .[].outputs.out)
-[[ $(< $path2/n) = 1 ]]
+[[ $(< "$path2"/n) = 1 ]]
 
 # Test impure derivations that depend on impure derivations.
 path3=$(nix build -L --no-link --json --file ./impure-derivations.nix impureOnImpure | jq -r .[].outputs.out)
-[[ $(< $path3/n) = X2 ]]
+[[ $(< "$path3"/n) = X2 ]]
 
 path4=$(nix build -L --no-link --json --file ./impure-derivations.nix impureOnImpure | jq -r .[].outputs.out)
-[[ $(< $path4/n) = X3 ]]
+[[ $(< "$path4"/n) = X3 ]]
 
 # Test that (self-)references work.
-[[ $(< $path4/symlink/bla) = 3 ]]
-[[ $(< $path4/self/n) = X3 ]]
+[[ $(< "$path4"/symlink/bla) = 3 ]]
+[[ $(< "$path4"/self/n) = X3 ]]
 
 # Input-addressed derivations cannot depend on impure derivations directly.
 (! nix build -L --no-link --json --file ./impure-derivations.nix inputAddressed 2>&1) | grep 'depends on impure derivation'
 
 drvPath=$(nix eval --json --file ./impure-derivations.nix impure.drvPath | jq -r .)
-[[ $(nix derivation show $drvPath | jq ".[\"$(basename "$drvPath")\"].outputs.out.impure") = true ]]
-[[ $(nix derivation show $drvPath | jq ".[\"$(basename "$drvPath")\"].outputs.stuff.impure") = true ]]
+[[ $(nix derivation show "$drvPath" | jq ".[\"$(basename "$drvPath")\"].outputs.out.impure") = true ]]
+[[ $(nix derivation show "$drvPath" | jq ".[\"$(basename "$drvPath")\"].outputs.stuff.impure") = true ]]
 
 # Fixed-output derivations *can* depend on impure derivations.
 path5=$(nix build -L --no-link --json --file ./impure-derivations.nix contentAddressed | jq -r .[].outputs.out)
-[[ $(< $path5) = X ]]
-[[ $(< $TEST_ROOT/counter) = 5 ]]
+[[ $(< "$path5") = X ]]
+[[ $(< "$TEST_ROOT"/counter) = 5 ]]
 
 # And they should not be rebuilt.
 path5=$(nix build -L --no-link --json --file ./impure-derivations.nix contentAddressed | jq -r .[].outputs.out)
-[[ $(< $path5) = X ]]
-[[ $(< $TEST_ROOT/counter) = 5 ]]
+[[ $(< "$path5") = X ]]
+[[ $(< "$TEST_ROOT"/counter) = 5 ]]
 
 # Input-addressed derivations can depend on fixed-output derivations that depend on impure derivations.
 path6=$(nix build -L --no-link --json --file ./impure-derivations.nix inputAddressedAfterCA | jq -r .[].outputs.out)
-[[ $(< $path6) = X ]]
-[[ $(< $TEST_ROOT/counter) = 5 ]]
+[[ $(< "$path6") = X ]]
+[[ $(< "$TEST_ROOT"/counter) = 5 ]]
 
 # Test nix/fetchurl.nix.
 path7=$(nix build -L --no-link --print-out-paths --expr "import <nix/fetchurl.nix> { impure = true; url = file://$PWD/impure-derivations.sh; }")
-cmp $path7 $PWD/impure-derivations.sh
+cmp "$path7" "$PWD"/impure-derivations.sh