diff --git a/source/ecs/manager.d b/source/ecs/manager.d
index 496b6ef..6aa36ee 100644
--- a/source/ecs/manager.d
+++ b/source/ecs/manager.d
@@ -673,31 +673,31 @@ class EntityManager
             foreach (iii, name; componentsInfo.req)
             {
                 ushort comp = components_map.get(cast(char[]) name, ushort.max);
-                assert(comp != ushort.max, "Can not register system: component not present");
+                assert(comp != ushort.max, "Can't register system \""~Sys.stringof~"\" due to non existing component \""~name~"\".");
                 system.m_components[iii] = comp;
             }
             foreach (iii, name; componentsInfo.excluded)
             {
                 ushort comp = components_map.get(cast(char[]) name, ushort.max);
-                assert(comp != ushort.max, "Can not register system: component not present");
+                assert(comp != ushort.max, "Can't register system \""~Sys.stringof~"\" due to non existing component \""~name~"\".");
                 system.m_excluded_components[iii] = comp;
             }
             foreach (iii, name; componentsInfo.optional)
             {
                 ushort comp = components_map.get(cast(char[]) name, ushort.max);
-                assert(comp != ushort.max, "Can not register system: component not present");
+                assert(comp != ushort.max, "Can't register system \""~Sys.stringof~"\" due to non existing component \""~name~"\".");
                 system.m_optional_components[iii] = comp;
             }
             foreach (iii, name; componentsInfo.readonly)
             {
                 ushort comp = components_map.get(cast(char[]) name, ushort.max);
-                assert(comp != ushort.max, "Can not register system: component not present");
+                assert(comp != ushort.max, "Can't register system \""~Sys.stringof~"\" due to non existing component \""~name~"\".");
                 system.m_read_only_components[iii] = comp;
             }
             foreach (iii, name; componentsInfo.mutable)
             {
                 ushort comp = components_map.get(cast(char[]) name, ushort.max);
-                assert(comp != ushort.max, "Can not register system: component not present");
+                assert(comp != ushort.max, "Can't register system \""~Sys.stringof~"\" due to non existing component \""~name~"\".");
                 system.m_modified_components[iii] = comp;
             }