diff --git a/src/main/java/com/dashjoin/jsonata/Functions.java b/src/main/java/com/dashjoin/jsonata/Functions.java
index 8dc7b7a..17fb147 100644
--- a/src/main/java/com/dashjoin/jsonata/Functions.java
+++ b/src/main/java/com/dashjoin/jsonata/Functions.java
@@ -231,7 +231,7 @@ static void string(StringBuilder b, Object arg, boolean prettify, String indent)
                     b.append("  ");
                 }
                 b.append('"');
-                b.append(e.getKey());
+                Utils.quote(e.getKey(), b);
                 b.append('"');
                 b.append(':');
                 if (prettify)
diff --git a/src/test/java/com/dashjoin/jsonata/StringTest.java b/src/test/java/com/dashjoin/jsonata/StringTest.java
index 5171329..6e43bfa 100644
--- a/src/test/java/com/dashjoin/jsonata/StringTest.java
+++ b/src/test/java/com/dashjoin/jsonata/StringTest.java
@@ -140,4 +140,11 @@ public void replaceTest() {
     Assertions.assertEquals("http://example.org/test", 
         jsonata("$replace($, /{par}/, '')").evaluate("http://example.org/test{par}"));
   }
+  
+  @Test
+  public void testFieldnameWithSpecialChar() {
+    Jsonata expr = jsonata("$ ~> |$|{}|");
+    Object o = Map.of("a\nb", "c\nd");
+    Assertions.assertEquals(o, expr.evaluate(o));
+  }
 }