diff --git a/core/save-git.c b/core/save-git.c
index a6f3e25cf..9bbf883e1 100644
--- a/core/save-git.c
+++ b/core/save-git.c
@@ -871,12 +871,14 @@ static void save_one_device(struct membuffer *b, const struct device *d)
 
 static void save_one_fingerprint(struct membuffer *b, unsigned int i)
 {
+	char *fp_data = fp_get_data(&fingerprint_table, i);
 	put_format(b, "fingerprint model=%08x serial=%08x deviceid=%08x diveid=%08x data=\"%s\"\n",
 		   fp_get_model(&fingerprint_table, i),
 		   fp_get_serial(&fingerprint_table, i),
 		   fp_get_deviceid(&fingerprint_table, i),
 		   fp_get_diveid(&fingerprint_table, i),
-		   fp_get_data(&fingerprint_table, i));
+		   fp_data);
+	free(fp_data);
 }
 
 static void save_settings(git_repository *repo, struct dir *tree)
diff --git a/core/save-xml.c b/core/save-xml.c
index 463f7372a..43b4ed30f 100644
--- a/core/save-xml.c
+++ b/core/save-xml.c
@@ -609,14 +609,14 @@ static void save_one_device(struct membuffer *b, const struct device *d)
 
 static void save_one_fingerprint(struct membuffer *b, int i)
 {
-	const char *data = fp_get_data(&fingerprint_table, i);
+	char *data = fp_get_data(&fingerprint_table, i);
 	put_format(b, "<fingerprint model='%08x' serial='%08x' deviceid='%08x' diveid='%08x' data='%s'/>\n",
 		   fp_get_model(&fingerprint_table, i),
 		   fp_get_serial(&fingerprint_table, i),
 		   fp_get_deviceid(&fingerprint_table, i),
 		   fp_get_diveid(&fingerprint_table, i),
 		   data);
-	free((void *)data);
+	free(data);
 }
 
 int save_dives(const char *filename)