diff --git a/src/main/java/org/json/XMLParserConfiguration.java b/src/main/java/org/json/XMLParserConfiguration.java
index 144c92a..b9e752c 100644
--- a/src/main/java/org/json/XMLParserConfiguration.java
+++ b/src/main/java/org/json/XMLParserConfiguration.java
@@ -24,6 +24,7 @@ SOFTWARE.
 */
 
 import java.util.Collections;
+import java.util.HashMap;
 import java.util.Map;
 
 
@@ -278,7 +279,8 @@ public class XMLParserConfiguration {
      */
     public XMLParserConfiguration withXsiTypeMap(final Map<String, XMLXsiTypeConverter<?>> xsiTypeMap) {
         XMLParserConfiguration newConfig = this.clone();
-        newConfig.xsiTypeMap = Collections.unmodifiableMap(xsiTypeMap);
+        Map<String, XMLXsiTypeConverter<?>> cloneXsiTypeMap = new HashMap<String, XMLXsiTypeConverter<?>>(xsiTypeMap);
+        newConfig.xsiTypeMap = Collections.unmodifiableMap(cloneXsiTypeMap);
         return newConfig;
     }
 }
diff --git a/src/test/java/org/json/junit/XMLTest.java b/src/test/java/org/json/junit/XMLTest.java
index 1cfd6b5..62ee516 100644
--- a/src/test/java/org/json/junit/XMLTest.java
+++ b/src/test/java/org/json/junit/XMLTest.java
@@ -1033,4 +1033,39 @@ public class XMLTest {
         Util.compareActualVsExpectedJsonObjects(actualJson,expectedJson);
     }
 
+    @Test
+    public void testToJsonWithXSITypeWhenTypeConversionNotEnabledOnOne() {
+        String originalXml = "<root><asString xsi:type=\"string\">12345</asString><asInt>54321</asInt></root>";
+        String expectedJsonString = "{\"root\":{\"asString\":\"12345\",\"asInt\":54321}}";
+        JSONObject expectedJson = new JSONObject(expectedJsonString);
+        Map<String, XMLXsiTypeConverter<?>> xsiTypeMap = new HashMap<String, XMLXsiTypeConverter<?>>();
+        xsiTypeMap.put("string", new XMLXsiTypeConverter<String>() {
+            @Override public String convert(final String value) {
+                return value;
+            }
+        });
+        JSONObject actualJson = XML.toJSONObject(originalXml, new XMLParserConfiguration().withXsiTypeMap(xsiTypeMap));
+        Util.compareActualVsExpectedJsonObjects(actualJson,expectedJson);
+    }
+
+    @Test
+    public void testXSITypeMapNotModifiable() {
+        Map<String, XMLXsiTypeConverter<?>> xsiTypeMap = new HashMap<String, XMLXsiTypeConverter<?>>();
+        XMLParserConfiguration config = new XMLParserConfiguration().withXsiTypeMap(xsiTypeMap);
+        xsiTypeMap.put("string", new XMLXsiTypeConverter<String>() {
+            @Override public String convert(final String value) {
+                return value;
+            }
+        });
+        assertEquals("Config Conversion Map size is expected to be 0", 0, config.getXsiTypeMap().size());
+
+        try {
+            config.getXsiTypeMap().put("boolean", new XMLXsiTypeConverter<Boolean>() {
+                @Override public Boolean convert(final String value) {
+                    return Boolean.valueOf(value);
+                }
+            });
+            fail("Expected to be unable to modify the config");
+        } catch (Exception ignored) { }
+    }
 }