diff --git a/tests/add.sh b/tests/add.sh
index 5c3eed7931a..e26e05843d7 100644
--- a/tests/add.sh
+++ b/tests/add.sh
@@ -9,7 +9,7 @@ echo $path2
 if test "$path1" != "$path2"; then
     echo "nix-store --add and --add-fixed mismatch"
     exit 1
-fi
+fi    
 
 path3=$(nix-store --add-fixed sha256 ./dummy)
 echo $path3
diff --git a/tests/check.nix b/tests/check.nix
index 32f0f9733a6..56c82e565a8 100644
--- a/tests/check.nix
+++ b/tests/check.nix
@@ -11,7 +11,7 @@ with import ./config.nix;
   };
 
   hashmismatch = import <nix/fetchurl.nix> {
-    url = "file://" + builtins.getEnv "TMPDIR" + "/dummy";
+    url = "file://" + toString ./dummy;
     sha256 = "0mdqa9w1p6cmli6976v4wi0sw9r4p5prkj7lzfd1877wk11c9c73";
   };
 
diff --git a/tests/check.sh b/tests/check.sh
index 45d29fd99a7..bc23a6634ca 100644
--- a/tests/check.sh
+++ b/tests/check.sh
@@ -34,9 +34,9 @@ nix-build check.nix -A fetchurl --no-out-link --repair --hashed-mirrors ''
 nix-build check.nix -A hashmismatch --no-out-link --hashed-mirrors '' || status=$?
 [ "$status" = "102" ]
 
-echo -n > $TMPDIR/dummy
+echo -n > ./dummy
 nix-build check.nix -A hashmismatch --no-out-link --hashed-mirrors ''
-echo 'Hello World' > $TMPDIR/dummy
+echo 'Hello World' > ./dummy
 
 nix-build check.nix -A hashmismatch --no-out-link --check --hashed-mirrors '' || status=$?
 [ "$status" = "102" ]