diff --git a/Transceiver52M/sigProcLib.cpp b/Transceiver52M/sigProcLib.cpp
index 5dc2def..cf72cae 100644
--- a/Transceiver52M/sigProcLib.cpp
+++ b/Transceiver52M/sigProcLib.cpp
@@ -33,6 +33,8 @@
 
 #include <Logger.h>
 
+using namespace GSM;
+
 #define TABLESIZE 1024
 
 /** Lookup tables for trigonometric approximation */