Fix bee8ded in error template file too
diff --git a/scripts/data_files/error.fmt b/scripts/data_files/error.fmt
index 413682f..b698427 100644
--- a/scripts/data_files/error.fmt
+++ b/scripts/data_files/error.fmt
@@ -29,9 +29,11 @@
 #include POLARSSL_CONFIG_FILE
 #endif
 
-#if defined(POLARSSL_ERROR_C)
-
+#if defined(POLARSSL_ERROR_C) || defined(POLARSSL_ERROR_STRERROR_DUMMY)
 #include "polarssl/error.h"
+#endif
+
+#if defined(POLARSSL_ERROR_C)
 
 HEADER_INCLUDED