diff --git a/src/protocols/Morse/Morse.cpp b/src/protocols/Morse/Morse.cpp
index 5b535ba6..1f1c3c70 100644
--- a/src/protocols/Morse/Morse.cpp
+++ b/src/protocols/Morse/Morse.cpp
@@ -1,5 +1,7 @@
 #include "Morse.h"
 
+#include <ctype.h>
+
 #if !defined(RADIOLIB_EXCLUDE_MORSE)
 
 MorseClient::MorseClient(PhysicalLayer* phy) {
diff --git a/src/protocols/RTTY/RTTY.cpp b/src/protocols/RTTY/RTTY.cpp
index 05dac1de..eff2d7ad 100644
--- a/src/protocols/RTTY/RTTY.cpp
+++ b/src/protocols/RTTY/RTTY.cpp
@@ -1,5 +1,7 @@
 #include "RTTY.h"
 
+#include <math.h>
+
 #if !defined(RADIOLIB_EXCLUDE_RTTY)
 
 RTTYClient::RTTYClient(PhysicalLayer* phy) {