diff -uNr php-8.1.0/ext/standard/proc_open.c php-8.1.0.mod/ext/standard/proc_open.c
--- php-8.1.0/ext/standard/proc_open.c	2021-11-23 19:56:11.000000000 +0100
+++ php-8.1.0.mod/ext/standard/proc_open.c	2021-11-26 05:56:50.783986679 +0100
@@ -1208,9 +1208,9 @@
 			execvp(ZSTR_VAL(command_str), argv);
 		} else {
 			if (env.envarray) {
-				execle("/bin/sh", "sh", "-c", ZSTR_VAL(command_str), NULL, env.envarray);
+				execle("@TERMUX_PREFIX@/bin/sh", "sh", "-c", ZSTR_VAL(command_str), NULL, env.envarray);
 			} else {
-				execl("/bin/sh", "sh", "-c", ZSTR_VAL(command_str), NULL);
+				execl("@TERMUX_PREFIX@/bin/sh", "sh", "-c", ZSTR_VAL(command_str), NULL);
 			}
 		}