diff --git a/SignalProcessing/FIRFilter.cpp b/SignalProcessing/FIRFilter.cpp
index 48bd3e5f1..382e11030 100644
--- a/SignalProcessing/FIRFilter.cpp
+++ b/SignalProcessing/FIRFilter.cpp
@@ -11,7 +11,7 @@
 #include <cmath>
 
 #ifndef M_PI
-#define M_PI 3.1415926f
+static constexpr float M_PI = 3.1415926f;
 #endif
 
 using namespace SignalProcessing;