diff --git a/include/backtrace/Backtrace.h b/include/backtrace/Backtrace.h
index 84b5631..e07d322 100644
--- a/include/backtrace/Backtrace.h
+++ b/include/backtrace/Backtrace.h
@@ -47,8 +47,13 @@
 // Forward declarations.
 class BacktraceImpl;
 
+#if defined(__APPLE__)
+struct __darwin_ucontext;
+typedef __darwin_ucontext ucontext_t;
+#else
 struct ucontext;
 typedef ucontext ucontext_t;
+#endif
 
 class Backtrace {
 public: