diff --git a/tools/output.c b/tools/output.c
index 4d5a5743205c659f8e17cf208a9414fbbbd4c938..6110b874fe450d224baf5d37125ed293037252e5 100644
--- a/tools/output.c
+++ b/tools/output.c
@@ -112,7 +112,7 @@ sexp_put_char(struct sexp_output *output, uint8_t c)
     sexp_put_raw_char(output, c);
 }
 
-static void
+void
 sexp_put_data(struct sexp_output *output,
 	      unsigned length, const uint8_t *data)
 {
diff --git a/tools/output.h b/tools/output.h
index c8e9a6789a8447ced3a806b83f45166e7a07bc03..79f147a06f1b14fab1dadc31246f7ac1a8722362 100644
--- a/tools/output.h
+++ b/tools/output.h
@@ -68,6 +68,10 @@ sexp_put_newline(struct sexp_output *output,
 void
 sexp_put_char(struct sexp_output *output, uint8_t c);
 
+void
+sexp_put_data(struct sexp_output *output,
+	      unsigned length, const uint8_t *data);
+
 void
 sexp_put_code_start(struct sexp_output *output,
 		    const struct nettle_armor *coding);