diff --git a/src/Entity.m b/src/Entity.m
index 983b6a7d808ecce4ac8be1c91f92599aaa8f1f44..11fdf5fa8e2520e8e6abced20979e5b753aacdf8 100644
--- a/src/Entity.m
+++ b/src/Entity.m
@@ -153,7 +153,8 @@ classdef Entity < handle
         name = prop{1}.name;
         if isfield(result, name)
           error("caosdb:NameCollision", ...
-                "Name collision: Two or more properties of the same name, cannot pack into struct.");
+                ["Name collision: Two or more properties of the same name, " ...
+                 "cannot pack into struct."]);
         end
         result = setfield(result, name, prop{1});
       end