diff --git a/tests/readfile-context.builder.sh b/tests/readfile-context.builder.sh
deleted file mode 100644
index 7084a08cb..000000000
--- a/tests/readfile-context.builder.sh
+++ /dev/null
@@ -1 +0,0 @@
-echo "$input" > $out
diff --git a/tests/readfile-context.nix b/tests/readfile-context.nix
index 600036a94..54cd1afd9 100644
--- a/tests/readfile-context.nix
+++ b/tests/readfile-context.nix
@@ -6,14 +6,23 @@ let
 
   dependent = mkDerivation {
     name = "dependent";
-    builder = ./readfile-context.builder.sh;
-    input = "${input}/hello";
+    buildCommand = ''
+      mkdir -p $out
+      echo -n "$input1" > "$out/file1"
+      echo -n "$input2" > "$out/file2"
+    '';
+    input1 = "${input}/hello";
+    input2 = "hello";
   };
 
   readDependent = mkDerivation {
-    name = "read-dependent";
-    builder = ./readfile-context.builder.sh;
-    input = builtins.readFile dependent;
+    # Will evaluate correctly because file2 doesn't have any references,
+    # even though the `dependent` derivation does.
+    name = builtins.readFile (dependent + "/file2");
+    buildCommand = ''
+      echo "$input" > "$out"
+    '';
+    input = builtins.readFile (dependent + "/file1");
   };
 
 in readDependent