diff --git a/README.md b/README.md
index 6129b422..655be463 100644
--- a/README.md
+++ b/README.md
@@ -39,7 +39,7 @@ Doxygen pages, please run the following command from the root of this repository
 ```shell
 doxygen docs/doxygen/config.doxyfile
 ```
-t
+
 ## Security
 
 See [CONTRIBUTING](CONTRIBUTING.md#security-issue-notifications) for more information.
diff --git a/source/portable/mbedtls/iot_pkcs11_mbedtls.c b/source/portable/mbedtls/iot_pkcs11_mbedtls.c
index 54eb2b1c..211dc597 100644
--- a/source/portable/mbedtls/iot_pkcs11_mbedtls.c
+++ b/source/portable/mbedtls/iot_pkcs11_mbedtls.c
@@ -929,7 +929,7 @@ static void prvFindObjectInListByHandle( CK_OBJECT_HANDLE xAppHandle,
 static CK_RV prvDeleteObjectFromList( CK_OBJECT_HANDLE xAppHandle )
 {
     CK_RV xResult = CKR_OK;
-    uint32_t ulGotSemaphore = 0UL;
+    int32_t lGotSemaphore = 0UL;
     uint32_t ulIndex = xAppHandle - 1UL;
 
     if( ulIndex >= pkcs11configMAX_NUM_OBJECTS )
@@ -939,10 +939,10 @@ static CK_RV prvDeleteObjectFromList( CK_OBJECT_HANDLE xAppHandle )
 
     if( xResult == CKR_OK )
     {
-        ulGotSemaphore = mbedtls_mutex_lock( &xP11Context.xObjectList.xMutex );
+        lGotSemaphore = mbedtls_mutex_lock( &xP11Context.xObjectList.xMutex );
     }
 
-    if( ulGotSemaphore == 0 )
+    if( lGotSemaphore == 0 )
     {
         if( xP11Context.xObjectList.xObjects[ ulIndex ].xHandle != CK_INVALID_HANDLE )
         {