%f confusingly enough takes a bool, not a float.
---
 ell/settings.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/ell/settings.c b/ell/settings.c
index 945dff7..dac45c9 100644
--- a/ell/settings.c
+++ b/ell/settings.c
@@ -1320,7 +1320,7 @@ LIB_EXPORT bool l_settings_set_float(struct l_settings *settings,
 {
 	L_AUTO_FREE_VAR(char *, buf);
 
-	buf = l_strdup_printf("%f", in);
+	buf = l_strdup_printf("%f", (double)in);
 
 	return l_settings_set_value(settings, group_name, key, buf);
 }
-- 
2.26.2