diff --git a/src/libfetchers/git.cc b/src/libfetchers/git.cc
index c1a21e764..7b7a1be35 100644
--- a/src/libfetchers/git.cc
+++ b/src/libfetchers/git.cc
@@ -485,6 +485,10 @@ struct GitInputScheme : InputScheme
                 }
                 input.attrs.insert_or_assign("ref", *head);
                 unlockedAttrs.insert_or_assign("ref", *head);
+            } else {
+                if (!input.getRev()) {
+                    unlockedAttrs.insert_or_assign("ref", input.getRef().value());
+                }
             }
 
             if (auto res = getCache()->lookup(store, unlockedAttrs)) {
diff --git a/tests/fetchGit.sh b/tests/fetchGit.sh
index 166bccfc7..4ceba0293 100644
--- a/tests/fetchGit.sh
+++ b/tests/fetchGit.sh
@@ -24,12 +24,14 @@ touch $repo/.gitignore
 git -C $repo add hello .gitignore
 git -C $repo commit -m 'Bla1'
 rev1=$(git -C $repo rev-parse HEAD)
+git -C $repo tag -a tag1 -m tag1
 
 echo world > $repo/hello
 git -C $repo commit -m 'Bla2' -a
 git -C $repo worktree add $TEST_ROOT/worktree
 echo hello >> $TEST_ROOT/worktree/hello
 rev2=$(git -C $repo rev-parse HEAD)
+git -C $repo tag -a tag2 -m tag2
 
 # Fetch a worktree
 unset _NIX_FORCE_HTTP
@@ -217,6 +219,16 @@ rev4_nix=$(nix eval --impure --raw --expr "(builtins.fetchGit { url = \"file://$
 path9=$(nix eval --impure --raw --expr "(builtins.fetchGit { url = \"file://$repo\"; ref = \"HEAD\"; name = \"foo\"; }).outPath")
 [[ $path9 =~ -foo$ ]]
 
+# Specifying a ref without a rev shouldn't pick a cached rev for a different ref
+export _NIX_FORCE_HTTP=1
+rev_tag1_nix=$(nix eval --impure --raw --expr "(builtins.fetchGit { url = \"file://$repo\"; ref = \"refs/tags/tag1\"; }).rev")
+rev_tag1=$(git -C $repo rev-parse refs/tags/tag1)
+[[ $rev_tag1_nix = $rev_tag1 ]]
+rev_tag2_nix=$(nix eval --impure --raw --expr "(builtins.fetchGit { url = \"file://$repo\"; ref = \"refs/tags/tag2\"; }).rev")
+rev_tag2=$(git -C $repo rev-parse refs/tags/tag2)
+[[ $rev_tag2_nix = $rev_tag2 ]]
+unset _NIX_FORCE_HTTP
+
 # should fail if there is no repo
 rm -rf $repo/.git
 (! nix eval --impure --raw --expr "(builtins.fetchGit \"file://$repo\").outPath")