diff --git a/tests/binary-cache.sh b/tests/binary-cache.sh
index b4a3601ec..b6951dd13 100644
--- a/tests/binary-cache.sh
+++ b/tests/binary-cache.sh
@@ -2,6 +2,7 @@ source common.sh
 
 clearStore
 
+# Create the binary cache.
 cacheDir=$TEST_ROOT/binary-cache
 rm -rf $cacheDir
 
@@ -9,10 +10,12 @@ outPath=$(nix-build dependencies.nix --no-out-link)
 
 nix-push --dest $cacheDir $outPath
 
+# Check that downloading works.
 clearStore
-
 rm -f $NIX_STATE_DIR/binary-cache*
 
+NIX_BINARY_CACHES="file://$cacheDir" nix-env -f dependencies.nix -qas \* | grep -- "--S"
+
 NIX_BINARY_CACHES="file://$cacheDir" nix-store -r $outPath
 
 nix-store --check-validity $outPath