diff -uNr isync-1.4.0/src/socket.c isync-1.4.0.mod/src/socket.c
--- isync-1.4.0/src/socket.c	2021-01-01 13:46:34.000000000 +0000
+++ isync-1.4.0.mod/src/socket.c	2021-02-05 21:07:36.435025222 +0000
@@ -510,7 +510,7 @@
 				_exit( 127 );
 			close( a[0] );
 			close( a[1] );
-			execl( "/bin/sh", "sh", "-c", conf->tunnel, (char *)0 );
+			execl( "@TERMUX_PREFIX@/bin/sh", "sh", "-c", conf->tunnel, (char *)0 );
 			_exit( 127 );
 		}