diff --git a/utils/us_math2.h b/utils/us_math2.h
index 080b5a9fb..5e6d6f1cc 100644
--- a/utils/us_math2.h
+++ b/utils/us_math2.h
@@ -105,7 +105,7 @@ class US_UTIL_EXTERN US_Math2
       //! \param y Pointer to an array of y values
       //! \param slope       Pointer to location to return the line's slope
       //! \param intercept   Pointer to location to return the line's y intercept
-      //! \param sigma       Pointer to location to return the standard deviation 
+      //! \param sigma       Pointer to location to return the square root of the population variance (not related to the fit result)
       //! \param correlation Pointer to location to return the correlation
       //! \param arraysize   Input array size
       static double linefit   ( double**, double**, double*, double*, double*,