diff --git a/tests/functional/fetchGit.sh b/tests/functional/fetchGit.sh
index 3bd4dcaa6..54be96da9 100755
--- a/tests/functional/fetchGit.sh
+++ b/tests/functional/fetchGit.sh
@@ -146,6 +146,9 @@ expect 102 nix eval --raw --expr "(builtins.fetchGit { url = $repo; rev = \"$rev
 path5=$(nix eval --raw --expr "(builtins.fetchGit { url = $repo; rev = \"$rev2\"; narHash = \"sha256-Hr8g6AqANb3xqX28eu1XnjK/3ab8Gv6TJSnkb1LezG9=\"; }).outPath")
 [[ $path = $path5 ]]
 
+# Ensure that NAR hashes are checked.
+expectStderr 102 nix eval --raw --expr "(builtins.fetchGit { url = $repo; rev = \"$rev2\"; narHash = \"sha256-Hr8g6AqANb4xqX28eu1XnjK/3ab8Gv6TJSnkb1LezG9=\"; }).outPath" | grepQuiet "error: NAR hash mismatch"
+
 # It's allowed to use only a narHash, but you should get a warning.
 expectStderr 0 nix eval --raw --expr "(builtins.fetchGit { url = $repo; ref = \"tag2\"; narHash = \"sha256-Hr8g6AqANb3xqX28eu1XnjK/3ab8Gv6TJSnkb1LezG9=\"; }).outPath" | grepQuiet "warning: Input .* is unlocked"