diff --git a/src/basic/vx_math/is_bad_data.h b/src/basic/vx_math/is_bad_data.h
index cb1c4afa8c..680bd5354e 100644
--- a/src/basic/vx_math/is_bad_data.h
+++ b/src/basic/vx_math/is_bad_data.h
@@ -101,7 +101,7 @@ inline double square(double v) {
 }
 
 inline double square_root(double v) {
-   return (is_bad_data(v) ? bad_data_double : sqrt(v));
+   return (is_bad_data(v) || v < 0 ? bad_data_double : sqrt(v));
 }