diff --git a/core/sys/windows/gdi32.odin b/core/sys/windows/gdi32.odin
index cf762bb18..141429483 100644
--- a/core/sys/windows/gdi32.odin
+++ b/core/sys/windows/gdi32.odin
@@ -350,4 +350,4 @@ NEWTEXTMETRICW :: struct {
 	ntmAvgWidth:        UINT,
 }
 
-FONTENUMPROCW :: #type proc(lpelf: ^ENUMLOGFONTW, lpntm: ^NEWTEXTMETRICW, FontType: DWORD, lParam: LPARAM) -> INT
+FONTENUMPROCW :: #type proc "system" (lpelf: ^ENUMLOGFONTW, lpntm: ^NEWTEXTMETRICW, FontType: DWORD, lParam: LPARAM) -> INT