diff --git a/Makefile b/Makefile
index 5024389..c45e218 100644
--- a/Makefile
+++ b/Makefile
@@ -89,8 +89,11 @@ roll: libio sysexits roll.o
 runlength: sysexits src/runlength.c usefulmacros
 	$(CC) $(CFLAGS) -o bin/runlength src/runlength.c
 
-simexec: sysexits src/simexec.c usefulmacros
-	$(CC) $(CFLAGS) -o bin/simexec src/simexec.c
+simexec.o: libio sysexits src/simexec.c
+	$(CC) $(CFLAGS) -c -o build/simexec.o src/simexec.c
+
+simexec: libio simexec.o
+	$(CC) $(CFLAGS) -o bin/simexec build/libio.o build/simexec.o
 
 streq: sysexits src/streq.c usefulmacros
 	$(CC) $(CFLAGS) -o bin/streq src/streq.c
diff --git a/lib/libio.c b/lib/libio.c
index 4bc9623..9b2291f 100644
--- a/lib/libio.c
+++ b/lib/libio.c
@@ -1,5 +1,6 @@
 #include <ctype.h>
 #include <unistd.h>
+#include "libio.h"
 
 static int
 _strlen(char *s){
@@ -50,6 +51,8 @@ put:	while(s > 0){
 		if((s /= 10) == 0)
 			r += write1(1, '\n');
 	}
+
+	return r;
 }
 
 int
diff --git a/lib/libio.h b/lib/libio.h
index 0dedf40..6083e0a 100644
--- a/lib/libio.h
+++ b/lib/libio.h
@@ -3,5 +3,5 @@
 int fdprint(int fd, char *s);
 int fdputd(int fd, int d);
 int fdputs(int fd, char *s);
-int parse_uint(char *s);
+unsigned int parse_uint(char *s);
 #endif /* ifndef _LIBIO_H */
diff --git a/src/simexec.c b/src/simexec.c
index 14a35dd..fe98992 100644
--- a/src/simexec.c
+++ b/src/simexec.c
@@ -12,7 +12,7 @@ int main(int argc, char *argv[]){
 		if(argv[0] == NULL)
 			argv[0] = program_name;
 		fdprint(2, argv[0]);
-		write(2, " [pathname], [argv...]\n", 23);
+		write(2, " [pathname] [argv...]\n", 22);
 		return EX_USAGE;
 	}