diff --git a/components/rgbd-sources/include/ftl/rgbd/source.hpp b/components/rgbd-sources/include/ftl/rgbd/source.hpp
index 885046c3a449f9e441ed0cb71e53c1cd0ae4fb85..65289fad96586ae0564129edb465975832eedf51 100644
--- a/components/rgbd-sources/include/ftl/rgbd/source.hpp
+++ b/components/rgbd-sources/include/ftl/rgbd/source.hpp
@@ -19,6 +19,8 @@ class Universe;
 
 namespace rgbd {
 
+static inline bool isValidDepth(float d) { return (d > 0.0f) && (d <= 40.0f); }
+
 class SnapshotReader;
 
 enum capability_t {