diff --git a/libunwind/src/UnwindRustSgx.h b/libunwind/src/UnwindRustSgx.h
index f965cebf4bb34..f48243fad9025 100644
--- a/libunwind/src/UnwindRustSgx.h
+++ b/libunwind/src/UnwindRustSgx.h
@@ -22,9 +22,9 @@
 
 // We have to use RWLock from rust repo, it is defined in:
 // src/libstd/sys/sgx/rwlock.rs.
-// rwlock.rs has compile time check to ensure sizeof(RWLock) = 128.
+// rwlock.rs has compile time check to ensure sizeof(RWLock) = 144.
 typedef struct {
-    unsigned char opaque[128];
+    unsigned char opaque[144];
 } RWLock;
 
 // The below is obtained by printing initialized bytes
diff --git a/libunwind/src/UnwindRustSgxSnprintf.c b/libunwind/src/UnwindRustSgxSnprintf.c
index a3246b02e2c29..8394f213f66cf 100644
--- a/libunwind/src/UnwindRustSgxSnprintf.c
+++ b/libunwind/src/UnwindRustSgxSnprintf.c
@@ -10,7 +10,9 @@
 #pragma GCC diagnostic ignored "-Wfloat-conversion"
 #pragma GCC diagnostic ignored "-Wsign-conversion"
 #pragma GCC diagnostic ignored "-Wstrict-overflow"
+#if __GNUC__ >= 7
 #pragma GCC diagnostic ignored "-Wimplicit-fallthrough"
+#endif
 
 /**************************************************************
  * Original: