diff --git a/libunwind/src/config.h b/libunwind/src/config.h
--- a/libunwind/src/config.h
+++ b/libunwind/src/config.h
@@ -124,6 +124,7 @@
 #if defined(_LIBUNWIND_REMEMBER_STACK_ALLOC) || defined(__APPLE__) ||          \
     defined(__linux__) || defined(__ANDROID__) || defined(__MINGW32__) ||      \
     defined(_LIBUNWIND_IS_BAREMETAL)
+#include <alloca.h>
 #define _LIBUNWIND_REMEMBER_ALLOC(_size) alloca(_size)
 #define _LIBUNWIND_REMEMBER_FREE(_ptr)                                         \
   do {                                                                         \