--- a/lib_pypy/_resource_build.py
+++ b/lib_pypy/_resource_build.py
@@ -75,2 +75,4 @@
 
+/* Termux addition: Add wait3() declaration used by busybox. Available in libc for 32-bit only. */
+static pid_t wait3(int* status, int options, struct rusage* rusage) { return wait4(-1, status, options, rusage); }
 """.replace('$RLIMIT_CONSTS', ''.join(rlimit_consts)))