diff --git a/libc/upstream-freebsd/android/include/freebsd-compat.h b/libc/upstream-freebsd/android/include/freebsd-compat.h
index 7acdf7c..8f0a307 100644
--- a/libc/upstream-freebsd/android/include/freebsd-compat.h
+++ b/libc/upstream-freebsd/android/include/freebsd-compat.h
@@ -18,6 +18,10 @@
 #define _BIONIC_FREEBSD_COMPAT_H_included
 
 #define _BSD_SOURCE
+
+#include <sys/cdefs.h>
+#include <stddef.h> // For size_t.
+
 #define REPLACE_GETOPT
 
 /*
@@ -40,4 +44,12 @@
 /* Redirect internal C library calls to the public function. */
 #define _nanosleep nanosleep
 
+/* FreeBSD has this as API, but we just use it internally. */
+void* reallocarray(void*, size_t, size_t);
+
+/* FreeBSD has this, but we can't really implement it correctly on Linux. */
+#define issetugid() 0
+
+#define ARG_MAX sysconf(_SC_ARG_MAX)
+
 #endif