diff --git a/libc/upstream-netbsd/android/include/netbsd-compat.h b/libc/upstream-netbsd/android/include/netbsd-compat.h
index 04bc728..0212d16 100644
--- a/libc/upstream-netbsd/android/include/netbsd-compat.h
+++ b/libc/upstream-netbsd/android/include/netbsd-compat.h
@@ -31,4 +31,7 @@
 #define __readlockenv() 0
 #define __unlockenv() 0
 
+#include <stddef.h>
+int reallocarr(void*, size_t, size_t);
+
 #endif