diff --git a/core/sys/windows/kernel32.odin b/core/sys/windows/kernel32.odin
index 9e5e5448b..05686b7d2 100644
--- a/core/sys/windows/kernel32.odin
+++ b/core/sys/windows/kernel32.odin
@@ -346,6 +346,13 @@ foreign kernel32 {
 	GenerateConsoleCtrlEvent :: proc(dwCtrlEvent: DWORD, dwProcessGroupId: DWORD) -> BOOL ---
 	FreeConsole :: proc() -> BOOL ---
 	GetConsoleWindow :: proc() -> HWND ---
+
+	GetDiskFreeSpaceExW :: proc(
+		lpDirectoryName: LPCWSTR,
+		lpFreeBytesAvailableToCaller: PULARGE_INTEGER,
+		lpTotalNumberOfBytes: PULARGE_INTEGER,
+		lpTotalNumberOfFreeBytes: PULARGE_INTEGER,
+	) -> BOOL ---
 }
 
 
diff --git a/core/sys/windows/types.odin b/core/sys/windows/types.odin
index d4983fd06..30cc62451 100644
--- a/core/sys/windows/types.odin
+++ b/core/sys/windows/types.odin
@@ -44,6 +44,7 @@ BOOLEAN :: distinct b8
 GROUP :: distinct c_uint
 LARGE_INTEGER :: distinct c_longlong
 ULARGE_INTEGER :: distinct c_ulonglong
+PULARGE_INTEGER :: ^ULARGE_INTEGER
 LONG :: c_long
 UINT :: c_uint
 INT  :: c_int