diff --git a/libraries/DataFlash/DataFlash_File.cpp b/libraries/DataFlash/DataFlash_File.cpp
index 73aa8dff2a..4316710c71 100644
--- a/libraries/DataFlash/DataFlash_File.cpp
+++ b/libraries/DataFlash/DataFlash_File.cpp
@@ -149,7 +149,9 @@ bool DataFlash_File::NeedErase(void)
 char *DataFlash_File::_log_file_name(uint16_t log_num)
 {
     char *buf = NULL;
-    asprintf(&buf, "%s/%u.BIN", _log_directory, (unsigned)log_num);
+    if (asprintf(&buf, "%s/%u.BIN", _log_directory, (unsigned)log_num) == 0) {
+        return NULL;
+    }
     return buf;
 }
 
@@ -160,7 +162,9 @@ char *DataFlash_File::_log_file_name(uint16_t log_num)
 char *DataFlash_File::_lastlog_file_name(void)
 {
     char *buf = NULL;
-    asprintf(&buf, "%s/LASTLOG.TXT", _log_directory);
+    if (asprintf(&buf, "%s/LASTLOG.TXT", _log_directory) == 0) {
+        return NULL;
+    }
     return buf;
 }
 
diff --git a/libraries/DataFlash/DataFlash_SITL.cpp b/libraries/DataFlash/DataFlash_SITL.cpp
index 219d30216b..847af6e5d0 100644
--- a/libraries/DataFlash/DataFlash_SITL.cpp
+++ b/libraries/DataFlash/DataFlash_SITL.cpp
@@ -16,6 +16,8 @@
 #include <assert.h>
 #include "DataFlash.h"
 
+#pragma GCC diagnostic ignored "-Wunused-result"
+
 #define DF_PAGE_SIZE 512
 #define DF_NUM_PAGES 16384