diff --git a/include/ntapi/nt_sem.h b/include/ntapi/nt_sem.h
index fa4cd3e..9e40a0b 100644
--- a/include/ntapi/nt_sem.h
+++ b/include/ntapi/nt_sem.h
@@ -40,10 +40,10 @@ typedef struct __attr_ptr_size_aligned__ _nt_sem_info {
 	int32_t		semadj;
 	nt_filetime	semotime;
 	nt_filetime	semctime;
-	uint32_t	ipcuid;
-	uint32_t	ipcgid;
-	uint32_t	ipccuid;
-	uint32_t	ipccgid;
+	uint64_t	ipcuid;
+	uint64_t	ipcgid;
+	uint64_t	ipccuid;
+	uint64_t	ipccgid;
 	uint32_t	ipcmode;
 	int32_t		ipcseq;
 	uint32_t	ntaccess;