diff --git a/libs/freetdm/src/dsp/bell202.c b/libs/freetdm/src/dsp/bell202.c
index 7f8faf536d..1213c2dcf5 100644
--- a/libs/freetdm/src/dsp/bell202.c
+++ b/libs/freetdm/src/dsp/bell202.c
@@ -42,9 +42,9 @@
 #include "bell202.h"
 #include "uart.h"
 
-#ifndef M_PI
-#define M_PI        3.14159265358979323846
-#endif
+#ifndef M_PI
+#define M_PI        3.14159265358979323846
+#endif
 
 // local constants
 #define	BELL202_MARK			1200