diff --git a/include/tccdefs.h b/include/tccdefs.h
index 2d42bea..83e3c38 100644
--- a/include/tccdefs.h
+++ b/include/tccdefs.h
@@ -88,9 +88,15 @@
     #define __GNUC_PATCHLEVEL__ 0
     #define __GNUC_STDC_INLINE__ 1
     #define __NO_TLS 1
+    #define __RUNETYPE_INTERNAL 1
 # if __SIZEOF_POINTER__ == 8
     /* FIXME, __int128_t is used by setjump */
     #define __int128_t struct { unsigned char _dummy[16] __attribute((aligned(16))); }
+    #define __SIZEOF_SIZE_T__ 8
+    #define __SIZEOF_PTRDIFF_T__ 8
+#else
+    #define __SIZEOF_SIZE_T__ 4
+    #define __SIZEOF_PTRDIFF_T__ 4
 # endif
 
 #elif defined __FreeBSD_kernel__
diff --git a/lib/bcheck.c b/lib/bcheck.c
index 0379b6e..91b7b12 100644
--- a/lib/bcheck.c
+++ b/lib/bcheck.c
@@ -226,10 +226,13 @@ typedef struct alloca_list_struct {
 #elif defined(__OpenBSD__)
 #define BOUND_TID_TYPE   pid_t
 #define BOUND_GET_TID    syscall (SYS_getthrid)
-#elif defined(__FreeBSD__) || defined(__NetBSD__)
+#elif defined(__FreeBSD__)
 #define BOUND_TID_TYPE   pid_t
-#define BOUND_GET_TID    0
-#elif defined(__i386__) || defined(__x86_64__) || defined(__arm__) || defined(__aarch64__) || defined(__riscv)
+#define BOUND_GET_TID    syscall (SYS_thr_self)
+#elif defined(__NetBSD__)
+#define BOUND_TID_TYPE   pid_t
+#define BOUND_GET_TID    syscall (SYS__lwp_self)
+#elif defined(__linux__)
 #define BOUND_TID_TYPE   pid_t
 #define BOUND_GET_TID    syscall (SYS_gettid)
 #else