diff --git a/src/libexpr/parser-state.hh b/src/libexpr/parser-state.hh
index c15da1a64180..d8287db9b278 100644
--- a/src/libexpr/parser-state.hh
+++ b/src/libexpr/parser-state.hh
@@ -300,7 +300,8 @@ inline Expr * ParserState::stripIndentation(const PosIdx pos,
         std::visit(overloaded { trimExpr, trimString }, i->second);
     }
 
-    /* If there is nothing at all, return the empty string directly */
+    // If there is nothing at all, return the empty string directly.
+    // This also ensures that equivalent empty strings result in the same ast, which is helpful when testing formatters.
     if (es2->size() == 0) {
         auto *const result = new ExprString("");
         delete es2;