diff --git a/lib/src/main/cpp/libkiwix/book.cpp b/lib/src/main/cpp/libkiwix/book.cpp
index 1c8e8b0..84d4508 100644
--- a/lib/src/main/cpp/libkiwix/book.cpp
+++ b/lib/src/main/cpp/libkiwix/book.cpp
@@ -95,6 +95,7 @@ METHOD0(jobjectArray, getIllustrations) {
   for (auto illu: illustrations) {
     auto wrapper = BUILD_WRAPPER("org/kiwix/libkiwix/Illustration", illu);
     env->SetObjectArrayElement(retArray, index++, wrapper);
+    env->DeleteLocalRef(wrapper);
   }
   return retArray;
 } CATCH_EXCEPTION(nullptr)
diff --git a/lib/src/main/cpp/libkiwix/library.cpp b/lib/src/main/cpp/libkiwix/library.cpp
index f65828b..20dc842 100644
--- a/lib/src/main/cpp/libkiwix/library.cpp
+++ b/lib/src/main/cpp/libkiwix/library.cpp
@@ -104,6 +104,7 @@ METHOD(jobjectArray, getBookmarks, jboolean onlyValidBookmarks) {
     shared_ptr<kiwix::Bookmark>* handle = new shared_ptr<kiwix::Bookmark>(new kiwix::Bookmark(std::move(bookmark)));
     jobject wrapper = env->NewObject(wrapperClass, initMethod, reinterpret_cast<jlong>(handle));
     env->SetObjectArrayElement(retArray, index++, wrapper);
+    env->DeleteLocalRef(wrapper);
   }
   return retArray;
 } CATCH_EXCEPTION(nullptr)
diff --git a/lib/src/main/cpp/utils.h b/lib/src/main/cpp/utils.h
index e5aee6f..f2c9e60 100644
--- a/lib/src/main/cpp/utils.h
+++ b/lib/src/main/cpp/utils.h
@@ -263,6 +263,7 @@ template<> struct JTypeArray<std::string>{
     for(size_t index=0; index<length; index++) {
       auto jElem = c2jni(data[index], env);
       env->SetObjectArrayElement(array, index, jElem);
+      env->DeleteLocalRef(jElem);
     }
   }
 };