diff --git a/gtsam/base/debug.h b/gtsam/base/debug.h
index 7fa943503..5f42580b1 100644
--- a/gtsam/base/debug.h
+++ b/gtsam/base/debug.h
@@ -47,6 +47,8 @@ namespace gtsam {
   // Non-guarded use led to crashes, and solved in commit cd35db2
   bool GTSAM_EXPORT guardedIsDebug(const std::string& s);
   void GTSAM_EXPORT guardedSetDebug(const std::string& s, const bool v);
+
+  // function to check if compiled version has debug information
   bool GTSAM_EXPORT isDebugVersion();
 }