diff --git a/src/libexpr/primops.cc b/src/libexpr/primops.cc
index 1197b6e13d51..6ee715b151ae 100644
--- a/src/libexpr/primops.cc
+++ b/src/libexpr/primops.cc
@@ -1555,6 +1555,9 @@ static RegisterPrimOp primop_pathExists({
     .doc = R"(
       Return `true` if the path *path* exists at evaluation time, and
       `false` otherwise.
+
+      If the path refers to a symlink, `pathExists` returns `true` without
+      checking the target of the symlink.
     )",
     .fun = prim_pathExists,
 });