diff --git a/core/encoding.c b/core/encoding.c
index ca317d1..5d055e2 100644
--- a/core/encoding.c
+++ b/core/encoding.c
@@ -3,7 +3,7 @@
 
 bool fx_wchar_is_number(fx_wchar c)
 {
-	return iswnumber((wchar_t)c);
+	return iswdigit((wchar_t)c);
 }
 
 bool fx_wchar_is_alpha(fx_wchar c)