diff --git a/qpkg/Makefile b/qpkg/Makefile
index 4b5e2c3..78932c0 100644
--- a/qpkg/Makefile
+++ b/qpkg/Makefile
@@ -1,4 +1,4 @@
-CFLAGS = -Wall -Wshadow -g -O
+CFLAGS = -Wall -Wshadow -Wmissing-prototypes -g -O
 # -O, so that we get data flow analysis, which helps to find more bugs
 #LDFLAGS=-pg
 
diff --git a/qpkg/jrb.c b/qpkg/jrb.c
index ec212a5..08428bb 100644
--- a/qpkg/jrb.c
+++ b/qpkg/jrb.c
@@ -228,7 +228,7 @@ static void mk_new_int(struct jrb *l, struct jrb *r, struct jrb *p, int il)
 }
 
 
-struct jrb *lprev(struct jrb *n)
+static struct jrb *lprev(struct jrb *n)
 {
 	if (ishead(n))
 		return n;
@@ -241,7 +241,7 @@ struct jrb *lprev(struct jrb *n)
 }
 
 
-struct jrb *rprev(struct jrb *n)
+static struct jrb *rprev(struct jrb *n)
 {
 	if (ishead(n))
 		return n;
diff --git a/qpkg/prereq.c b/qpkg/prereq.c
index a6865b9..1f96d9f 100644
--- a/qpkg/prereq.c
+++ b/qpkg/prereq.c
@@ -7,6 +7,7 @@
 #include "id.h"
 #include "qpkg.h"
 #include "util.h"
+#include "prereq.h"
 
 
 struct list {