diff --git a/library/dhm.c b/library/dhm.c
index a4715d1..f7e71f3 100644
--- a/library/dhm.c
+++ b/library/dhm.c
@@ -542,7 +542,10 @@
     if( fread( *buf, 1, *n, f ) != *n )
     {
         fclose( f );
+
+        mbedtls_zeroize( *buf, *n + 1 );
         mbedtls_free( *buf );
+
         return( MBEDTLS_ERR_DHM_FILE_IO_ERROR );
     }