diff --git a/src/pg_proctab.c b/src/pg_proctab.c
index 7fc4724..31ca9ab 100644
--- a/src/pg_proctab.c
+++ b/src/pg_proctab.c
@@ -21,6 +21,7 @@
 #include <fcntl.h>
 #include <sys/param.h>
 #include <executor/spi.h>
+#include <pwd.h>
 #include "pg_proctab.h"
 
 #define FULLCOMM_LEN 1024