diff --git a/src/test/java/com/persiantools4j/objectmapper/JacksonObjectMapperWrapperTest.java b/src/test/java/com/persiantools4j/objectmapper/JacksonObjectMapperWrapperTest.java
index e68868b..58181b8 100644
--- a/src/test/java/com/persiantools4j/objectmapper/JacksonObjectMapperWrapperTest.java
+++ b/src/test/java/com/persiantools4j/objectmapper/JacksonObjectMapperWrapperTest.java
@@ -42,6 +42,7 @@ private static Stream<Arguments> deserializationCases() {
         return Stream.of(
                 Arguments.of(null, null),
                 Arguments.of("", ""),
+                Arguments.of(" ", ""),
                 Arguments.of(testStr, StringUtils.normalizePersian(testStr)),
                 Arguments.of(dontNeedToNormalizeStr, dontNeedToNormalizeStr)
         );