diff --git a/src/svxlink/trx/DtmfDecoderTest.cpp b/src/svxlink/trx/DtmfDecoderTest.cpp
index 7c298d5..7fe9242 100644
--- a/src/svxlink/trx/DtmfDecoderTest.cpp
+++ b/src/svxlink/trx/DtmfDecoderTest.cpp
@@ -2,6 +2,7 @@
 #include <string>
 #include <fstream>
 #include <cstdlib>
+#include <cstdint>
 #include <cmath>
 
 #include <AsyncConfig.h>