diff --git a/core/sys/windows/winmm.odin b/core/sys/windows/winmm.odin
index 64ace19fc..380a5e9ed 100644
--- a/core/sys/windows/winmm.odin
+++ b/core/sys/windows/winmm.odin
@@ -5,7 +5,14 @@ foreign import winmm "system:Winmm.lib"
 
 @(default_calling_convention="stdcall")
 foreign winmm {
+	timeGetDevCaps  :: proc(ptc: LPTIMECAPS, cbtc: UINT) -> MMRESULT ---
 	timeBeginPeriod :: proc(uPeriod: UINT) -> MMRESULT ---
 	timeEndPeriod   :: proc(uPeriod: UINT) -> MMRESULT ---
 	timeGetTime     :: proc() -> DWORD ---
 }
+
+LPTIMECAPS :: ^TIMECAPS
+TIMECAPS :: struct {
+	wPeriodMin: UINT,
+	wPeriodMax: UINT,
+}
\ No newline at end of file