diff --git a/src/SparkFunBME280.cpp b/src/SparkFunBME280.cpp
index 235e259..1e624da 100644
--- a/src/SparkFunBME280.cpp
+++ b/src/SparkFunBME280.cpp
@@ -20,6 +20,7 @@ Distributed as-is; no warranty is given.
 ******************************************************************************/
 //See SparkFunBME280.h for additional topology notes.
 
+#include <math.h>
 #include "SparkFunBME280.h"
 
 //****************************************************************************//