diff --git a/libraries/DataFlash/DataFlash.h b/libraries/DataFlash/DataFlash.h
index b813ccadc1..965a23f53f 100644
--- a/libraries/DataFlash/DataFlash.h
+++ b/libraries/DataFlash/DataFlash.h
@@ -39,8 +39,9 @@ public:
     virtual void get_log_boundaries(uint8_t log_num, uint16_t & start_page, uint16_t & end_page) = 0;
     virtual uint8_t get_num_logs(void) = 0;
     virtual void start_new_log(void) = 0;
-    virtual uint16_t log_read_process(uint16_t start_page, uint16_t end_page, 
-                              void (*callback)(uint8_t msgid)) = 0;
+    virtual uint16_t log_read_process(uint8_t log_num,
+                                      uint16_t start_page, uint16_t end_page, 
+                                      void (*callback)(uint8_t msgid)) = 0;
     virtual void DumpPageInfo(AP_HAL::BetterStream *port) = 0;
     virtual void ShowDeviceInfo(AP_HAL::BetterStream *port) = 0;
 
diff --git a/libraries/DataFlash/DataFlash_Block.h b/libraries/DataFlash/DataFlash_Block.h
index 9a795d0ce9..3fac74fb13 100644
--- a/libraries/DataFlash/DataFlash_Block.h
+++ b/libraries/DataFlash/DataFlash_Block.h
@@ -40,7 +40,8 @@ public:
     void get_log_boundaries(uint8_t log_num, uint16_t & start_page, uint16_t & end_page);
     uint8_t get_num_logs(void);
     void start_new_log(void);
-    uint16_t log_read_process(uint16_t start_page, uint16_t end_page, 
+    uint16_t log_read_process(uint8_t log_num,
+                              uint16_t start_page, uint16_t end_page, 
                               void (*callback)(uint8_t msgid));
     void DumpPageInfo(AP_HAL::BetterStream *port);
     void ShowDeviceInfo(AP_HAL::BetterStream *port);
diff --git a/libraries/DataFlash/LogFile.cpp b/libraries/DataFlash/LogFile.cpp
index 5ee326c59c..c51a3d1014 100644
--- a/libraries/DataFlash/LogFile.cpp
+++ b/libraries/DataFlash/LogFile.cpp
@@ -234,8 +234,11 @@ uint16_t DataFlash_Block::find_last_page_of_log(uint16_t log_number)
   Read the DataFlash log memory
   Call the callback() function on each log message found in the page
   range. Return the number of log messages found
+
+  Note that for the block oriented backend the log_num is ignored
 */
-uint16_t DataFlash_Block::log_read_process(uint16_t start_page, uint16_t end_page, 
+uint16_t DataFlash_Block::log_read_process(uint8_t log_num,
+                                           uint16_t start_page, uint16_t end_page, 
                                            void (*callback)(uint8_t msgid))
 {
     uint8_t log_step = 0;