diff --git a/src/libexpr/primops/fetchTree.cc b/src/libexpr/primops/fetchTree.cc
index f040a3510..d108d7d50 100644
--- a/src/libexpr/primops/fetchTree.cc
+++ b/src/libexpr/primops/fetchTree.cc
@@ -395,7 +395,8 @@ static RegisterPrimOp primop_fetchGit({
 
       - `shallow` (default: `false`)
 
-        A Boolean parameter that specifies whether fetching a shallow clone is allowed.
+        A Boolean parameter that specifies whether fetching from a shallow remote repository is allowed.
+        This still performs a full clone of what is available on the remote.
 
       - `allRefs`