diff --git a/src/java/davmail/util/StringUtil.java b/src/java/davmail/util/StringUtil.java
index a7b7ea39..f24a9fd1 100644
--- a/src/java/davmail/util/StringUtil.java
+++ b/src/java/davmail/util/StringUtil.java
@@ -388,18 +388,21 @@ public final class StringUtil {
 
     /**
      * Remove quotes if present on value.
+     *
      * @param value input value
      * @return unquoted string
      */
     public static String removeQuotes(String value) {
         String result = value;
-        if (result.startsWith("\"") || result.startsWith("{") || result.startsWith("(")) {
-            result = result.substring(1);
-        }
-        if (result.endsWith("\"") || result.endsWith("}") || result.endsWith(")")) {
-            result = result.substring(0, result.length() - 1);
+        if (result != null) {
+            if (result.startsWith("\"") || result.startsWith("{") || result.startsWith("(")) {
+                result = result.substring(1);
+            }
+            if (result.endsWith("\"") || result.endsWith("}") || result.endsWith(")")) {
+                result = result.substring(0, result.length() - 1);
+            }
         }
         return result;
     }
-    
+
 }