diff --git a/websh.c b/websh.c
index 50e3eeb..94a0ff0 100644
--- a/websh.c
+++ b/websh.c
@@ -6,6 +6,12 @@
  * @brief Formats program output for the web.
  */
 
+#include <stdio.h>
+#include <stdlib.h>
+
+#include <errno.h>
+#include <signal.h>
+
 int main(int argc, char *argv[])
 {