diff --git a/lib/dns/rbtdb.c b/lib/dns/rbtdb.c
index 3b0da11c0a..bdf5303e58 100644
--- a/lib/dns/rbtdb.c
+++ b/lib/dns/rbtdb.c
@@ -27,6 +27,10 @@
 
 /* #define inline */
 
+#ifdef HAVE_INTTYPES_H
+#include <inttypes.h> /* uintptr_t */
+#endif
+
 #include <isc/crc64.h>
 #include <isc/event.h>
 #include <isc/heap.h>
diff --git a/lib/isc/unix/socket.c b/lib/isc/unix/socket.c
index 78ff4d7fd2..ac19d217ce 100644
--- a/lib/isc/unix/socket.c
+++ b/lib/isc/unix/socket.c
@@ -39,6 +39,9 @@
 #include <stdlib.h>
 #include <string.h>
 #include <unistd.h>
+#ifdef HAVE_INTTYPES_H
+#include <inttypes.h> /* uintptr_t */
+#endif
 
 #include <isc/buffer.h>
 #include <isc/bufferlist.h>