diff --git a/src/cborpretty.c b/src/cborpretty.c
index 02b5706b..0c2b1107 100644
--- a/src/cborpretty.c
+++ b/src/cborpretty.c
@@ -29,6 +29,9 @@
 #include "compilersupport_p.h"
 #include "utf8_p.h"
 
+// Include sys/types.h before inttypes.h to work around issue with
+// certain versions of GCC and newlib which causes omission of PRIx64
+#include <sys/types.h>
 #include <inttypes.h>
 #include <string.h>
 
diff --git a/src/cbortojson.c b/src/cbortojson.c
index 9a1cccfd..bc9b6f66 100644
--- a/src/cbortojson.c
+++ b/src/cbortojson.c
@@ -31,6 +31,9 @@
 #include "cborinternal_p.h"
 #include <memory.h>
 
+// Include sys/types.h before inttypes.h to work around issue with
+// certain versions of GCC and newlib which causes omission of PRIx64
+#include <sys/types.h>
 #include <inttypes.h>
 #include <stdio.h>
 #include <stdlib.h>