diff --git a/pinot-common/src/main/java/org/apache/pinot/common/function/scalar/JsonFunctions.java b/pinot-common/src/main/java/org/apache/pinot/common/function/scalar/JsonFunctions.java
index fa50cc6c4868..5effbe3e5448 100644
--- a/pinot-common/src/main/java/org/apache/pinot/common/function/scalar/JsonFunctions.java
+++ b/pinot-common/src/main/java/org/apache/pinot/common/function/scalar/JsonFunctions.java
@@ -76,7 +76,7 @@ public static String toJsonMapStr(@Nullable Map map)
   /**
    * Convert object to Json String
    */
-  @ScalarFunction(nullableParameters = true)
+  @ScalarFunction
   public static String jsonFormat(Object object)
       throws JsonProcessingException {
     return JsonUtils.objectToString(object);
diff --git a/pinot-core/src/test/java/org/apache/pinot/core/data/function/JsonFunctionsTest.java b/pinot-core/src/test/java/org/apache/pinot/core/data/function/JsonFunctionsTest.java
index fa9f6dfced2b..6aa8bcbe3d8f 100644
--- a/pinot-core/src/test/java/org/apache/pinot/core/data/function/JsonFunctionsTest.java
+++ b/pinot-core/src/test/java/org/apache/pinot/core/data/function/JsonFunctionsTest.java
@@ -137,4 +137,19 @@ public Object[][] jsonFunctionsDataProvider()
     });
     return inputs.toArray(new Object[0][]);
   }
+
+  @Test(description = "jsonFormat(Java null) should return Java null")
+  public void jsonFormatWithJavaNullReturnsJavaNull() {
+    GenericRow row = new GenericRow();
+    row.putValue("jsonMap", null);
+    testFunction("json_format(jsonMap)", Lists.newArrayList("jsonMap"), row, null);
+  }
+
+  @Test(description = "jsonFormat(JSON null) should return \"null\"")
+  public void jsonFormatWithJsonNullReturnsStringNull()
+      throws IOException {
+    GenericRow row = new GenericRow();
+    row.putValue("jsonMap", JsonUtils.stringToJsonNode("null"));
+    testFunction("json_format(jsonMap)", Lists.newArrayList("jsonMap"), row, "null");
+  }
 }
diff --git a/pinot-spi/src/main/java/org/apache/pinot/spi/annotations/ScalarFunction.java b/pinot-spi/src/main/java/org/apache/pinot/spi/annotations/ScalarFunction.java
index f0d14f7dd98f..46a743d52c79 100644
--- a/pinot-spi/src/main/java/org/apache/pinot/spi/annotations/ScalarFunction.java
+++ b/pinot-spi/src/main/java/org/apache/pinot/spi/annotations/ScalarFunction.java
@@ -46,11 +46,16 @@
 
   boolean enabled() default true;
 
-  // If empty, FunctionsRegistry registers the method name as function name;
-  // If not empty, FunctionsRegistry only registers the function names specified here, the method name is ignored.
+  /**
+   * If empty, FunctionsRegistry registers the method name as function name;
+   * If not empty, FunctionsRegistry only registers the function names specified here, the method name is ignored.
+   */
   String[] names() default {};
 
-  // Whether the scalar function expects and can handle null arguments.
+  /**
+   * Whether the scalar function expects and can handle null arguments.
+   *
+   */
   boolean nullableParameters() default false;
 
   boolean isPlaceholder() default false;