diff --git a/ChangeLog b/ChangeLog
index 110398ec2..4b266d572 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -27,6 +27,7 @@ Bugfix
    * Other minor issues (found by Peter Vaskovic)
    * Fix symlink command for cross compiling with CMake (found by Andre
      Heinecke)
+   * Fix DER output of gen_key app (found by Gergely Budai)
 
 = PolarSSL 1.3.7 released on 2014-05-02
 Features
diff --git a/programs/pkey/gen_key.c b/programs/pkey/gen_key.c
index 7c8efef6d..2f3ba358a 100644
--- a/programs/pkey/gen_key.c
+++ b/programs/pkey/gen_key.c
@@ -143,7 +143,7 @@ static int write_private_key( pk_context *key, const char *output_file )
             return( ret );
 
         len = ret;
-        c = output_buf + sizeof(output_buf) - len - 1;
+        c = output_buf + sizeof(output_buf) - len;
     }
 
     if( ( f = fopen( output_file, "w" ) ) == NULL )