diff --git a/README.md b/README.md
index 4d863d7..ec6549d 100644
--- a/README.md
+++ b/README.md
@@ -6,12 +6,12 @@ Slow down input to output
 Install
 -------
 
-  # make clean install
+    # make clean install
 
 Usage
 -----
 
-  $ slow [-t usec] [-f]
+    $ slow [-t usec] [-f]
 
 -t usec : Define sleep between each bytes in micro-second. Default to 1 second.
 
diff --git a/config.mk b/config.mk
index 6a37cc8..bd994da 100644
--- a/config.mk
+++ b/config.mk
@@ -11,9 +11,9 @@ INCS =
 LIBS =
 
 # flags
-CPPFLAGS = -DVERSION=\"${VERSION}\"
+CPPFLAGS = -DVERSION=\"${VERSION}\" -D_XOPEN_SOURCE=500
 CFLAGS = -std=c99 -pedantic -Wall -Os ${INCS} ${CPPFLAGS}
-LDFLAGS = -s ${LIBS}
+LDFLAGS = -static -s ${LIBS}
 
 # compiler and linker
 CC = cc
diff --git a/slow.c b/slow.c
index 71b1fef..d58f409 100644
--- a/slow.c
+++ b/slow.c
@@ -1,4 +1,3 @@
-#define _XOPEN_SOURCE 500
 #include <stdlib.h>
 #include <stdio.h>
 #include <unistd.h>
@@ -7,12 +6,18 @@
 
 char *argv0;
 
-void usage() {
+static void usage(void);
+
+void
+usage()
+{
 	fprintf(stderr, "usage: %s [-t usec] [-f]\n", argv0);
-	exit(EXIT_FAILURE);
+	exit(1);
 }
 
-int main(int argc, char *argv[]) {
+int
+main(int argc, char *argv[])
+{
 	char            buffer;
 	size_t          nread;
 	useconds_t      useconds        = 1000000; // default 1 second
@@ -31,18 +36,20 @@ int main(int argc, char *argv[]) {
 
 	while ((nread = fread(&buffer, 1, sizeof buffer, stdin)) > 0) {
 		usleep(useconds);
+
 		if (fwrite(&buffer, 1, nread, stdout) != nread) {
 			fprintf(stderr, "stdout: write error");
-			exit(EXIT_FAILURE);
+			exit(1);
 		}
-		if (flush) {
+
+		if (flush)
 			fflush(stdout);
-		}
-	}
-	if (ferror(stdin)) {
-		fprintf(stderr, "stdin: read error");
-		exit(EXIT_FAILURE);
 	}
 
-	return EXIT_SUCCESS;
+	if (ferror(stdin)) {
+		fprintf(stderr, "stdin: read error");
+		exit(1);
+	}
+
+	return 0;
 }