diff --git a/src/protocols/Print/Print.cpp b/src/protocols/Print/Print.cpp
index 9d0fa558..a6a71ae6 100644
--- a/src/protocols/Print/Print.cpp
+++ b/src/protocols/Print/Print.cpp
@@ -1,5 +1,9 @@
 #include "Print.h"
 
+#include <string.h>
+#include <ctype.h>
+#include <math.h>
+
 size_t RadioLibPrint::print(ITA2String& ita2) {
   uint8_t enc = this->encoding;
   this->encoding = RADIOLIB_ITA2;