diff --git a/.gitignore b/.gitignore
index 11a80ab5b..de1183977 100644
--- a/.gitignore
+++ b/.gitignore
@@ -102,9 +102,6 @@ perl/Makefile.config
 /tests/functional/restricted-innocent
 /tests/functional/shell
 /tests/functional/shell.drv
-/tests/functional/config.nix
-/tests/functional/ca/config.nix
-/tests/functional/dyn-drv/config.nix
 /tests/functional/repl-result-out
 /tests/functional/debugger-test-out
 /tests/functional/test-libstoreconsumer/test-libstoreconsumer
diff --git a/tests/functional/build-hook-ca-fixed.nix b/tests/functional/build-hook-ca-fixed.nix
index 427ec2c31..0ce6d9b12 100644
--- a/tests/functional/build-hook-ca-fixed.nix
+++ b/tests/functional/build-hook-ca-fixed.nix
@@ -1,6 +1,6 @@
 { busybox }:
 
-with import "${builtins.getEnv "_NIX_TEST_BUILD_DIR"}/config.nix";
+with import ./config.nix;
 
 let
 
diff --git a/tests/functional/build-hook.nix b/tests/functional/build-hook.nix
index 1f0e17a3b..99a13aee4 100644
--- a/tests/functional/build-hook.nix
+++ b/tests/functional/build-hook.nix
@@ -1,6 +1,6 @@
 { busybox, contentAddressed ? false }:
 
-with import "${builtins.getEnv "_NIX_TEST_BUILD_DIR"}/config.nix";
+with import ./config.nix;
 
 let
 
diff --git a/tests/functional/ca/config.nix b/tests/functional/ca/config.nix
new file mode 100644
index 000000000..451fbae4f
--- /dev/null
+++ b/tests/functional/ca/config.nix
@@ -0,0 +1,2 @@
+# Shim to get generated file
+import "${builtins.getEnv "_NIX_TEST_BUILD_DIR"}/ca/config.nix"
diff --git a/tests/functional/ca/content-addressed.nix b/tests/functional/ca/content-addressed.nix
index 411ebb86b..2559c562f 100644
--- a/tests/functional/ca/content-addressed.nix
+++ b/tests/functional/ca/content-addressed.nix
@@ -1,4 +1,4 @@
-with import "${builtins.getEnv "_NIX_TEST_BUILD_DIR"}/ca/config.nix";
+with import ./config.nix;
 
 let mkCADerivation = args: mkDerivation ({
     __contentAddressed = true;
diff --git a/tests/functional/ca/nix-run.sh b/tests/functional/ca/nix-run.sh
index 21c09117e..e6638cc91 100755
--- a/tests/functional/ca/nix-run.sh
+++ b/tests/functional/ca/nix-run.sh
@@ -6,7 +6,4 @@ flakeDir="$TEST_HOME/flake"
 mkdir -p "${flakeDir}"
 cp flake.nix "${_NIX_TEST_BUILD_DIR}/ca/config.nix" content-addressed.nix "${flakeDir}"
 
-# `config.nix` cannot be gotten via build dir / env var (runs afoul pure eval). Instead get from flake.
-removeBuildDirRef "$flakeDir"/*.nix
-
 nix run --no-write-lock-file "path:${flakeDir}#runnable"
diff --git a/tests/functional/ca/nondeterministic.nix b/tests/functional/ca/nondeterministic.nix
index 740be4bd2..d6d099a3e 100644
--- a/tests/functional/ca/nondeterministic.nix
+++ b/tests/functional/ca/nondeterministic.nix
@@ -1,4 +1,4 @@
-with import "${builtins.getEnv "_NIX_TEST_BUILD_DIR"}/ca/config.nix";
+with import ./config.nix;
 
 let mkCADerivation = args: mkDerivation ({
     __contentAddressed = true;
diff --git a/tests/functional/ca/racy.nix b/tests/functional/ca/racy.nix
index cadd98675..555a15484 100644
--- a/tests/functional/ca/racy.nix
+++ b/tests/functional/ca/racy.nix
@@ -2,7 +2,7 @@
 # build it at once.
 
 
-with import "${builtins.getEnv "_NIX_TEST_BUILD_DIR"}/ca/config.nix";
+with import ./config.nix;
 
 mkDerivation {
   name = "simple";
diff --git a/tests/functional/check-refs.nix b/tests/functional/check-refs.nix
index 54957f635..89690e456 100644
--- a/tests/functional/check-refs.nix
+++ b/tests/functional/check-refs.nix
@@ -1,4 +1,4 @@
-with import "${builtins.getEnv "_NIX_TEST_BUILD_DIR"}/config.nix";
+with import ./config.nix;
 
 rec {
 
diff --git a/tests/functional/check-reqs.nix b/tests/functional/check-reqs.nix
index 4e059f5a4..41436cb48 100644
--- a/tests/functional/check-reqs.nix
+++ b/tests/functional/check-reqs.nix
@@ -1,4 +1,4 @@
-with import "${builtins.getEnv "_NIX_TEST_BUILD_DIR"}/config.nix";
+with import ./config.nix;
 
 rec {
   dep1 = mkDerivation {
diff --git a/tests/functional/check.nix b/tests/functional/check.nix
index 13638eae8..ddab8eea9 100644
--- a/tests/functional/check.nix
+++ b/tests/functional/check.nix
@@ -1,6 +1,6 @@
 {checkBuildId ? 0}:
 
-with import "${builtins.getEnv "_NIX_TEST_BUILD_DIR"}/config.nix";
+with import ./config.nix;
 
 {
   nondeterministic = mkDerivation {
diff --git a/tests/functional/chroot-store.sh b/tests/functional/chroot-store.sh
index 8c2a969d3..46e91f0aa 100755
--- a/tests/functional/chroot-store.sh
+++ b/tests/functional/chroot-store.sh
@@ -39,9 +39,6 @@ EOF
 
     cp simple.nix shell.nix simple.builder.sh "${config_nix}" "$flakeDir/"
 
-    # `config.nix` cannot be gotten via build dir / env var (runs afoul pure eval). Instead get from flake.
-    removeBuildDirRef "$flakeDir"/*.nix
-
     TODO_NixOS
 
     outPath=$(nix build --print-out-paths --no-link --sandbox-paths '/nix? /bin? /lib? /lib64? /usr?' --store "$TEST_ROOT/x" path:"$flakeDir")
diff --git a/tests/functional/common/functions.sh b/tests/functional/common/functions.sh
index 286bb58e8..7195149cb 100644
--- a/tests/functional/common/functions.sh
+++ b/tests/functional/common/functions.sh
@@ -343,15 +343,6 @@ count() {
   echo $#
 }
 
-# Sometimes, e.g. due to pure eval, restricted eval, or sandboxing, we
-# cannot look up `config.nix` in the build dir, and have to instead get
-# it from the current directory. (In this case, the current directly
-# will be somewhere in `$TEST_ROOT`.)
-removeBuildDirRef() {
-  # shellcheck disable=SC2016 # The ${} in this is Nix, not shell
-  sed -i -e 's,"${builtins.getEnv "_NIX_TEST_BUILD_DIR"}/[^ ]*config.nix",./config.nix,' "$@"
-}
-
 trap onError ERR
 
 fi # COMMON_FUNCTIONS_SH_SOURCED
diff --git a/tests/functional/config.nix b/tests/functional/config.nix
new file mode 100644
index 000000000..5d1cb74ec
--- /dev/null
+++ b/tests/functional/config.nix
@@ -0,0 +1,2 @@
+# Shim to get generated file
+import "${builtins.getEnv "_NIX_TEST_BUILD_DIR"}/config.nix"
diff --git a/tests/functional/dependencies.nix b/tests/functional/dependencies.nix
index db06321da..be1a7ae9a 100644
--- a/tests/functional/dependencies.nix
+++ b/tests/functional/dependencies.nix
@@ -1,5 +1,5 @@
 { hashInvalidator ? "" }:
-with import "${builtins.getEnv "_NIX_TEST_BUILD_DIR"}/config.nix";
+with import ./config.nix;
 
 let {
 
diff --git a/tests/functional/dyn-drv/config.nix b/tests/functional/dyn-drv/config.nix
new file mode 100644
index 000000000..8ec2c67ea
--- /dev/null
+++ b/tests/functional/dyn-drv/config.nix
@@ -0,0 +1,2 @@
+# Shim to get generated file
+import "${builtins.getEnv "_NIX_TEST_BUILD_DIR"}/dyn-drv/config.nix"
diff --git a/tests/functional/dyn-drv/old-daemon-error-hack.nix b/tests/functional/dyn-drv/old-daemon-error-hack.nix
index 7d3ccf7e4..c9d4a62d4 100644
--- a/tests/functional/dyn-drv/old-daemon-error-hack.nix
+++ b/tests/functional/dyn-drv/old-daemon-error-hack.nix
@@ -1,4 +1,4 @@
-with import "${builtins.getEnv "_NIX_TEST_BUILD_DIR"}/dyn-drv/config.nix";
+with import ./config.nix;
 
 # A simple content-addressed derivation.
 # The derivation can be arbitrarily modified by passing a different `seed`,
diff --git a/tests/functional/dyn-drv/recursive-mod-json.nix b/tests/functional/dyn-drv/recursive-mod-json.nix
index 0e778aa7f..c6a24ca4f 100644
--- a/tests/functional/dyn-drv/recursive-mod-json.nix
+++ b/tests/functional/dyn-drv/recursive-mod-json.nix
@@ -1,4 +1,4 @@
-with import "${builtins.getEnv "_NIX_TEST_BUILD_DIR"}/dyn-drv/config.nix";
+with import ./config.nix;
 
 let innerName = "foo"; in
 
diff --git a/tests/functional/dyn-drv/text-hashed-output.nix b/tests/functional/dyn-drv/text-hashed-output.nix
index aa46fff61..99203b518 100644
--- a/tests/functional/dyn-drv/text-hashed-output.nix
+++ b/tests/functional/dyn-drv/text-hashed-output.nix
@@ -1,4 +1,4 @@
-with import "${builtins.getEnv "_NIX_TEST_BUILD_DIR"}/dyn-drv/config.nix";
+with import ./config.nix;
 
 # A simple content-addressed derivation.
 # The derivation can be arbitrarily modified by passing a different `seed`,
diff --git a/tests/functional/export-graph.nix b/tests/functional/export-graph.nix
index 97ffe73a9..64fe36bd1 100644
--- a/tests/functional/export-graph.nix
+++ b/tests/functional/export-graph.nix
@@ -1,4 +1,4 @@
-with import "${builtins.getEnv "_NIX_TEST_BUILD_DIR"}/config.nix";
+with import ./config.nix;
 
 rec {
 
diff --git a/tests/functional/extra-sandbox-profile.nix b/tests/functional/extra-sandbox-profile.nix
index 5f0e4753f..aa680b918 100644
--- a/tests/functional/extra-sandbox-profile.nix
+++ b/tests/functional/extra-sandbox-profile.nix
@@ -1,6 +1,6 @@
 { destFile, seed }:
 
-with import "${builtins.getEnv "_NIX_TEST_BUILD_DIR"}/config.nix";
+with import ./config.nix;
 
 mkDerivation {
   name = "simple";
diff --git a/tests/functional/failing.nix b/tests/functional/failing.nix
index 8b7990679..d25e2d6b6 100644
--- a/tests/functional/failing.nix
+++ b/tests/functional/failing.nix
@@ -1,5 +1,5 @@
 { busybox }:
-with import "${builtins.getEnv "_NIX_TEST_BUILD_DIR"}/config.nix";
+with import ./config.nix;
 let
 
   mkDerivation = args:
diff --git a/tests/functional/filter-source.nix b/tests/functional/filter-source.nix
index dcef9c4e2..907163639 100644
--- a/tests/functional/filter-source.nix
+++ b/tests/functional/filter-source.nix
@@ -1,4 +1,4 @@
-with import "${builtins.getEnv "_NIX_TEST_BUILD_DIR"}/config.nix";
+with import ./config.nix;
 
 mkDerivation {
   name = "filter";
diff --git a/tests/functional/fixed.nix b/tests/functional/fixed.nix
index f70b89091..a920a2167 100644
--- a/tests/functional/fixed.nix
+++ b/tests/functional/fixed.nix
@@ -1,4 +1,4 @@
-with import "${builtins.getEnv "_NIX_TEST_BUILD_DIR"}/config.nix";
+with import ./config.nix;
 
 rec {
 
diff --git a/tests/functional/flakes/bundle.sh b/tests/functional/flakes/bundle.sh
index 61aa040e7..2946aea35 100755
--- a/tests/functional/flakes/bundle.sh
+++ b/tests/functional/flakes/bundle.sh
@@ -4,9 +4,6 @@ source common.sh
 
 cp ../simple.nix ../simple.builder.sh "${config_nix}" "$TEST_HOME"
 
-# `config.nix` cannot be gotten via build dir / env var (runs afoul pure eval). Instead get from flake.
-removeBuildDirRef "$TEST_HOME"/*.nix
-
 cd "$TEST_HOME"
 
 cat <<EOF > flake.nix
diff --git a/tests/functional/flakes/common.sh b/tests/functional/flakes/common.sh
index 8af72f2ad..cc9b2e466 100644
--- a/tests/functional/flakes/common.sh
+++ b/tests/functional/flakes/common.sh
@@ -35,9 +35,6 @@ writeSimpleFlake() {
 EOF
 
     cp ../simple.nix ../shell.nix ../simple.builder.sh "${config_nix}" "$flakeDir/"
-
-    # `config.nix` cannot be gotten via build dir / env var (runs afoul pure eval). Instead get from flake.
-    removeBuildDirRef "$flakeDir"/*.nix
 }
 
 createSimpleGitFlake() {
diff --git a/tests/functional/flakes/config.sh b/tests/functional/flakes/config.sh
index 48f1c7a85..ab2d9f47c 100755
--- a/tests/functional/flakes/config.sh
+++ b/tests/functional/flakes/config.sh
@@ -3,7 +3,6 @@
 source common.sh
 
 cp ../simple.nix ../simple.builder.sh "${config_nix}" $TEST_HOME
-removeBuildDirRef "$TEST_HOME/simple.nix"
 
 cd $TEST_HOME
 
diff --git a/tests/functional/flakes/develop.sh b/tests/functional/flakes/develop.sh
index 2e75081d4..b3e438e99 100755
--- a/tests/functional/flakes/develop.sh
+++ b/tests/functional/flakes/develop.sh
@@ -27,9 +27,6 @@ EOF
 mkdir -p "$TEST_HOME/nixpkgs"
 cp "${config_nix}" ../shell.nix "$TEST_HOME/nixpkgs"
 
-# `config.nix` cannot be gotten via build dir / env var (runs afoul pure eval). Instead get from flake.
-removeBuildDirRef "$TEST_HOME/nixpkgs"/*.nix
-
 cat <<EOF >"$TEST_HOME/nixpkgs/flake.nix"
 {
     outputs = {self}: {
diff --git a/tests/functional/flakes/run.sh b/tests/functional/flakes/run.sh
index 2077c965b..c92ddca2b 100755
--- a/tests/functional/flakes/run.sh
+++ b/tests/functional/flakes/run.sh
@@ -8,8 +8,6 @@ clearStore
 rm -rf $TEST_HOME/.cache $TEST_HOME/.config $TEST_HOME/.local
 
 cp ../shell-hello.nix "${config_nix}" $TEST_HOME
-# `config.nix` cannot be gotten via build dir / env var (runs afoul pure eval). Instead get from flake.
-removeBuildDirRef "$TEST_HOME"/*.nix
 cd $TEST_HOME
 
 cat <<EOF > flake.nix
diff --git a/tests/functional/fod-failing.nix b/tests/functional/fod-failing.nix
index 7881a3fbf..37c04fe12 100644
--- a/tests/functional/fod-failing.nix
+++ b/tests/functional/fod-failing.nix
@@ -1,4 +1,4 @@
-with import "${builtins.getEnv "_NIX_TEST_BUILD_DIR"}/config.nix";
+with import ./config.nix;
 rec {
   x1 = mkDerivation {
     name = "x1";
diff --git a/tests/functional/gc-concurrent.nix b/tests/functional/gc-concurrent.nix
index a5c3c97c3..0aba1f983 100644
--- a/tests/functional/gc-concurrent.nix
+++ b/tests/functional/gc-concurrent.nix
@@ -1,4 +1,4 @@
-with import "${builtins.getEnv "_NIX_TEST_BUILD_DIR"}/config.nix";
+with import ./config.nix;
 
 { lockFifo ? null }:
 
diff --git a/tests/functional/gc-runtime.nix b/tests/functional/gc-runtime.nix
index 2603fafdf..ee5980bdf 100644
--- a/tests/functional/gc-runtime.nix
+++ b/tests/functional/gc-runtime.nix
@@ -1,4 +1,4 @@
-with import "${builtins.getEnv "_NIX_TEST_BUILD_DIR"}/config.nix";
+with import ./config.nix;
 
 mkDerivation {
   name = "gc-runtime";
diff --git a/tests/functional/hermetic.nix b/tests/functional/hermetic.nix
index dafe8ad9f..d1dccdff3 100644
--- a/tests/functional/hermetic.nix
+++ b/tests/functional/hermetic.nix
@@ -5,7 +5,7 @@
 , withFinalRefs ? false
 }:
 
-with import "${builtins.getEnv "_NIX_TEST_BUILD_DIR"}/config.nix";
+with import ./config.nix;
 
 let
   contentAddressedByDefault = builtins.getEnv "NIX_TESTS_CA_BY_DEFAULT" == "1";
diff --git a/tests/functional/ifd.nix b/tests/functional/ifd.nix
index c84ffbc66..d0b9b54ad 100644
--- a/tests/functional/ifd.nix
+++ b/tests/functional/ifd.nix
@@ -1,4 +1,4 @@
-with import "${builtins.getEnv "_NIX_TEST_BUILD_DIR"}/config.nix";
+with import ./config.nix;
 import (
   mkDerivation {
     name = "foo";
diff --git a/tests/functional/import-from-derivation.nix b/tests/functional/import-from-derivation.nix
index 8864fb30a..cc53451cf 100644
--- a/tests/functional/import-from-derivation.nix
+++ b/tests/functional/import-from-derivation.nix
@@ -1,4 +1,4 @@
-with import "${builtins.getEnv "_NIX_TEST_BUILD_DIR"}/config.nix";
+with import ./config.nix;
 
 rec {
   bar = mkDerivation {
diff --git a/tests/functional/impure-derivations.nix b/tests/functional/impure-derivations.nix
index 04710323f..98547e6c1 100644
--- a/tests/functional/impure-derivations.nix
+++ b/tests/functional/impure-derivations.nix
@@ -1,4 +1,4 @@
-with import "${builtins.getEnv "_NIX_TEST_BUILD_DIR"}/config.nix";
+with import ./config.nix;
 
 rec {
 
diff --git a/tests/functional/impure-env.nix b/tests/functional/impure-env.nix
index 6b9e5a825..2b0380ed7 100644
--- a/tests/functional/impure-env.nix
+++ b/tests/functional/impure-env.nix
@@ -1,6 +1,6 @@
 { var, value }:
 
-with import "${builtins.getEnv "_NIX_TEST_BUILD_DIR"}/config.nix";
+with import ./config.nix;
 
 mkDerivation {
   name = "test";
diff --git a/tests/functional/linux-sandbox-cert-test.nix b/tests/functional/linux-sandbox-cert-test.nix
index e506b6a0f..2fc083ea9 100644
--- a/tests/functional/linux-sandbox-cert-test.nix
+++ b/tests/functional/linux-sandbox-cert-test.nix
@@ -1,6 +1,6 @@
 { mode }:
 
-with import "${builtins.getEnv "_NIX_TEST_BUILD_DIR"}/config.nix";
+with import ./config.nix;
 
 mkDerivation (
   {
diff --git a/tests/functional/multiple-outputs.nix b/tests/functional/multiple-outputs.nix
index 19ae2a45d..6ba7c523d 100644
--- a/tests/functional/multiple-outputs.nix
+++ b/tests/functional/multiple-outputs.nix
@@ -1,4 +1,4 @@
-with import "${builtins.getEnv "_NIX_TEST_BUILD_DIR"}/config.nix";
+with import ./config.nix;
 
 rec {
 
diff --git a/tests/functional/nar-access.nix b/tests/functional/nar-access.nix
index 78972bd36..9948abe59 100644
--- a/tests/functional/nar-access.nix
+++ b/tests/functional/nar-access.nix
@@ -1,4 +1,4 @@
-with import "${builtins.getEnv "_NIX_TEST_BUILD_DIR"}/config.nix";
+with import ./config.nix;
 
 rec {
     a = mkDerivation {
diff --git a/tests/functional/nix-build-examples.nix b/tests/functional/nix-build-examples.nix
index aaea8fc07..e54dbbf62 100644
--- a/tests/functional/nix-build-examples.nix
+++ b/tests/functional/nix-build-examples.nix
@@ -1,4 +1,4 @@
-with import "${builtins.getEnv "_NIX_TEST_BUILD_DIR"}/config.nix";
+with import ./config.nix;
 
 rec {
 
diff --git a/tests/functional/parallel.nix b/tests/functional/parallel.nix
index 1f2411c92..23f142059 100644
--- a/tests/functional/parallel.nix
+++ b/tests/functional/parallel.nix
@@ -1,6 +1,6 @@
 {sleepTime ? 3}:
 
-with import "${builtins.getEnv "_NIX_TEST_BUILD_DIR"}/config.nix";
+with import ./config.nix;
 
 let
 
diff --git a/tests/functional/path.nix b/tests/functional/path.nix
index b23300f90..883c3c41b 100644
--- a/tests/functional/path.nix
+++ b/tests/functional/path.nix
@@ -1,4 +1,4 @@
-with import "${builtins.getEnv "_NIX_TEST_BUILD_DIR"}/config.nix";
+with import ./config.nix;
 
 mkDerivation {
   name = "filter";
diff --git a/tests/functional/readfile-context.nix b/tests/functional/readfile-context.nix
index b8f4a4c27..54cd1afd9 100644
--- a/tests/functional/readfile-context.nix
+++ b/tests/functional/readfile-context.nix
@@ -1,4 +1,4 @@
-with import "${builtins.getEnv "_NIX_TEST_BUILD_DIR"}/config.nix";
+with import ./config.nix;
 
 let
 
diff --git a/tests/functional/restricted.sh b/tests/functional/restricted.sh
index 63bf56cd7..00ee4ddc8 100755
--- a/tests/functional/restricted.sh
+++ b/tests/functional/restricted.sh
@@ -12,10 +12,6 @@ mkdir -p "$TEST_ROOT/nix"
 cp ./simple.nix "$TEST_ROOT/nix"
 cp ./simple.builder.sh "$TEST_ROOT/nix"
 cp "${config_nix}" "$TEST_ROOT/nix"
-simple_nix="$TEST_ROOT/nix/simple.nix"
-# N.B. redefine
-config_nix="$TEST_ROOT/nix/config.nix"
-removeBuildDirRef "${simple_nix}"
 cd "$TEST_ROOT/nix"
 
 nix-instantiate --restrict-eval ./simple.nix -I src=.
diff --git a/tests/functional/search.nix b/tests/functional/search.nix
index 3c3564bda..fea6e7a7a 100644
--- a/tests/functional/search.nix
+++ b/tests/functional/search.nix
@@ -1,4 +1,4 @@
-with import "${builtins.getEnv "_NIX_TEST_BUILD_DIR"}/config.nix";
+with import ./config.nix;
 
 {
   hello = mkDerivation rec {
diff --git a/tests/functional/secure-drv-outputs.nix b/tests/functional/secure-drv-outputs.nix
index cd111c315..b4ac8ff53 100644
--- a/tests/functional/secure-drv-outputs.nix
+++ b/tests/functional/secure-drv-outputs.nix
@@ -1,4 +1,4 @@
-with import "${builtins.getEnv "_NIX_TEST_BUILD_DIR"}/config.nix";
+with import ./config.nix;
 
 {
 
diff --git a/tests/functional/shell-hello.nix b/tests/functional/shell-hello.nix
index fa02e2bb4..c920d7cb4 100644
--- a/tests/functional/shell-hello.nix
+++ b/tests/functional/shell-hello.nix
@@ -1,4 +1,4 @@
-with import "${builtins.getEnv "_NIX_TEST_BUILD_DIR"}/config.nix";
+with import ./config.nix;
 
 rec {
   hello = mkDerivation {
diff --git a/tests/functional/shell.nix b/tests/functional/shell.nix
index f6622a487..9cae14b78 100644
--- a/tests/functional/shell.nix
+++ b/tests/functional/shell.nix
@@ -1,6 +1,6 @@
 { inNixShell ? false, contentAddressed ? false, fooContents ? "foo" }:
 
-let cfg = import "${builtins.getEnv "_NIX_TEST_BUILD_DIR"}/config.nix"; in
+let cfg = import ./config.nix; in
 with cfg;
 
 let
diff --git a/tests/functional/simple-failing.nix b/tests/functional/simple-failing.nix
index 228971734..d176c9c51 100644
--- a/tests/functional/simple-failing.nix
+++ b/tests/functional/simple-failing.nix
@@ -1,4 +1,4 @@
-with import "${builtins.getEnv "_NIX_TEST_BUILD_DIR"}/config.nix";
+with import ./config.nix;
 
 mkDerivation {
   name = "simple-failing";
diff --git a/tests/functional/simple.nix b/tests/functional/simple.nix
index 96237695c..2035ca294 100644
--- a/tests/functional/simple.nix
+++ b/tests/functional/simple.nix
@@ -1,4 +1,4 @@
-with import "${builtins.getEnv "_NIX_TEST_BUILD_DIR"}/config.nix";
+with import ./config.nix;
 
 mkDerivation {
   name = "simple";
diff --git a/tests/functional/structured-attrs-shell.nix b/tests/functional/structured-attrs-shell.nix
index 7ed28c03f..57c1e6bd2 100644
--- a/tests/functional/structured-attrs-shell.nix
+++ b/tests/functional/structured-attrs-shell.nix
@@ -1,4 +1,4 @@
-with import "${builtins.getEnv "_NIX_TEST_BUILD_DIR"}/config.nix";
+with import ./config.nix;
 let
   dep = mkDerivation {
     name = "dep";
diff --git a/tests/functional/structured-attrs.nix b/tests/functional/structured-attrs.nix
index ae461c21a..e93139a44 100644
--- a/tests/functional/structured-attrs.nix
+++ b/tests/functional/structured-attrs.nix
@@ -1,4 +1,4 @@
-with import "${builtins.getEnv "_NIX_TEST_BUILD_DIR"}/config.nix";
+with import ./config.nix;
 
 let
 
diff --git a/tests/functional/symlink-derivation.nix b/tests/functional/symlink-derivation.nix
index 96765d355..e9a74cdce 100644
--- a/tests/functional/symlink-derivation.nix
+++ b/tests/functional/symlink-derivation.nix
@@ -1,4 +1,4 @@
-with import "${builtins.getEnv "_NIX_TEST_BUILD_DIR"}/config.nix";
+with import ./config.nix;
 
 let
   foo_in_store = builtins.toFile "foo" "foo";
diff --git a/tests/functional/timeout.nix b/tests/functional/timeout.nix
index ad71e61e2..d0e949e31 100644
--- a/tests/functional/timeout.nix
+++ b/tests/functional/timeout.nix
@@ -1,4 +1,4 @@
-with import "${builtins.getEnv "_NIX_TEST_BUILD_DIR"}/config.nix";
+with import ./config.nix;
 
 {
 
diff --git a/tests/functional/user-envs.nix b/tests/functional/user-envs.nix
index c8e846d4b..46f8b51dd 100644
--- a/tests/functional/user-envs.nix
+++ b/tests/functional/user-envs.nix
@@ -2,7 +2,7 @@
 { foo ? "foo"
 }:
 
-with import "${builtins.getEnv "_NIX_TEST_BUILD_DIR"}/config.nix";
+with import ./config.nix;
 
 assert foo == "foo";