diff --git a/src/main/cpp/_nix_based/jssc.cpp b/src/main/cpp/_nix_based/jssc.cpp
index f0d77d437..87fb1a753 100644
--- a/src/main/cpp/_nix_based/jssc.cpp
+++ b/src/main/cpp/_nix_based/jssc.cpp
@@ -530,8 +530,18 @@ JNIEXPORT jboolean JNICALL Java_jssc_SerialNativeInterface_setDTR
  */
 JNIEXPORT jboolean JNICALL Java_jssc_SerialNativeInterface_writeBytes
   (JNIEnv *env, jobject, jlong portHandle, jbyteArray buffer){
+    if( buffer == NULL ){
+        jclass exClz = env->FindClass("java/lang/NullPointerException");
+        if( exClz != NULL ) env->ThrowNew(exClz, "buffer");
+        return 0;
+    }
     jboolean ret = JNI_FALSE;
     jbyte* jBuffer = env->GetByteArrayElements(buffer, JNI_FALSE);
+    if( jBuffer == NULL ){
+        jclass exClz = env->FindClass("java/lang/RuntimeException");
+        if( exClz != NULL ) env->ThrowNew(exClz, "jni->GetByteArrayElements() failed");
+        return 0;
+    }
     jint bufferSize = env->GetArrayLength(buffer);
     jint result = write(portHandle, jBuffer, (size_t)bufferSize);
     if( result == -1 ){
diff --git a/src/main/cpp/windows/jssc.cpp b/src/main/cpp/windows/jssc.cpp
index e608e060e..6c9f298b0 100644
--- a/src/main/cpp/windows/jssc.cpp
+++ b/src/main/cpp/windows/jssc.cpp
@@ -236,9 +236,19 @@ JNIEXPORT jboolean JNICALL Java_jssc_SerialNativeInterface_writeBytes
     HANDLE hComm = (HANDLE)portHandle;
     DWORD lpNumberOfBytesTransferred;
     DWORD lpNumberOfBytesWritten;
-    OVERLAPPED *overlapped = new OVERLAPPED();
     jboolean returnValue = JNI_FALSE;
+    if( buffer == NULL ){
+        jclass exClz = env->FindClass("java/lang/NullPointerException");
+        if( exClz != NULL ) env->ThrowNew(exClz, "buffer");
+        return 0;
+    }
     jbyte* jBuffer = env->GetByteArrayElements(buffer, JNI_FALSE);
+    if( jBuffer == NULL ){
+        jclass exClz = env->FindClass("java/lang/RuntimeException");
+        if( exClz != NULL ) env->ThrowNew(exClz, "jni->GetByteArrayElements() failed");
+        return 0;
+    }
+    OVERLAPPED *overlapped = new OVERLAPPED();
     overlapped->hEvent = CreateEventA(NULL, true, false, NULL);
     if(WriteFile(hComm, jBuffer, (DWORD)env->GetArrayLength(buffer), &lpNumberOfBytesWritten, overlapped)){
         returnValue = JNI_TRUE;
diff --git a/src/test/java/jssc/SerialNativeInterfaceTest.java b/src/test/java/jssc/SerialNativeInterfaceTest.java
index 541e2f753..5bbcb2c1f 100644
--- a/src/test/java/jssc/SerialNativeInterfaceTest.java
+++ b/src/test/java/jssc/SerialNativeInterfaceTest.java
@@ -88,4 +88,9 @@ public void throwsIllegalArgumentExceptionIfPortHandleIllegalOsx() throws Except
         }
     }
 
+    @Test(expected = java.lang.NullPointerException.class)
+    public void throwsNpeIfPassedBufferIsNull() throws Exception {
+        new SerialNativeInterface().writeBytes(1, null);
+    }
+
 }