diff --git a/src/support/lassert.h b/src/support/lassert.h
index 5a47edfdb4..5e152e05bc 100644
--- a/src/support/lassert.h
+++ b/src/support/lassert.h
@@ -21,7 +21,7 @@ namespace lyx {
 
 /******************************************************************************
 
-LyX has five different macros that can be used to make assertions. The behave
+LyX has five different macros that can be used to make assertions. They behave
 the same way in devel mode: They assert. The differences between them are how
 they behave in release mode.