diff --git a/library/psa_crypto_its.h b/library/psa_crypto_its.h
index 44d5198..3809787 100644
--- a/library/psa_crypto_its.h
+++ b/library/psa_crypto_its.h
@@ -91,6 +91,7 @@
  * \param[in] data_offset       The starting offset of the data requested
  * \param[in] data_length       the amount of data requested (and the minimum allocated size of the `p_data` buffer)
  * \param[out] p_data           The buffer where the data will be placed upon successful completion
+ * \param[out] p_data_length    The amount of data returned in the p_data buffer
  *
  *
  * \return      A status indicating the success/failure of the operation
@@ -106,7 +107,8 @@
 psa_status_t psa_its_get(psa_storage_uid_t uid,
                          uint32_t data_offset,
                          uint32_t data_length,
-                         void *p_data);
+                         void *p_data,
+                         size_t *p_data_length );
 
 /**
  * \brief Retrieve the metadata about the provided uid
diff --git a/library/psa_crypto_storage.c b/library/psa_crypto_storage.c
index babc5bb..3c33c1d 100644
--- a/library/psa_crypto_storage.c
+++ b/library/psa_crypto_storage.c
@@ -96,12 +96,15 @@
     psa_status_t status;
     psa_storage_uid_t data_identifier = psa_its_identifier_of_slot( key );
     struct psa_storage_info_t data_identifier_info;
+    size_t data_length = 0;
 
     status = psa_its_get_info( data_identifier, &data_identifier_info );
     if( status  != PSA_SUCCESS )
         return( status );
 
-    status = psa_its_get( data_identifier, 0, (uint32_t) data_size, data );
+    status = psa_its_get( data_identifier, 0, (uint32_t) data_size, data, &data_length );
+    if( data_size  != data_length )
+        return( PSA_ERROR_STORAGE_FAILURE );
 
     return( status );
 }
diff --git a/library/psa_its_file.c b/library/psa_its_file.c
index 8cdf783..05ca8af 100644
--- a/library/psa_its_file.c
+++ b/library/psa_its_file.c
@@ -44,7 +44,9 @@
 #include <stdio.h>
 #include <string.h>
 
+#if !defined(PSA_ITS_STORAGE_PREFIX)
 #define PSA_ITS_STORAGE_PREFIX ""
+#endif
 
 #define PSA_ITS_STORAGE_FILENAME_PATTERN "%08lx%08lx"
 #define PSA_ITS_STORAGE_SUFFIX ".psa_its"
@@ -137,7 +139,8 @@
 psa_status_t psa_its_get( psa_storage_uid_t uid,
                           uint32_t data_offset,
                           uint32_t data_length,
-                          void *p_data )
+                          void *p_data,
+                          size_t *p_data_length )
 {
     psa_status_t status;
     FILE *stream = NULL;
@@ -172,6 +175,8 @@
     if( n != data_length )
         goto exit;
     status = PSA_SUCCESS;
+    if( p_data_length != NULL )
+        *p_data_length = n;
 
 exit:
     if( stream != NULL )