diff --git a/Project.toml b/Project.toml
index 1d931de..52070d4 100644
--- a/Project.toml
+++ b/Project.toml
@@ -28,3 +28,6 @@ julia = "1"
 
 [extras]
 Test = "8dfed614-e22c-5e08-85e1-65c5234f0b40"
+
+[targets]
+test = ["Test"]
\ No newline at end of file
diff --git a/docs/src/release_notes.md b/docs/src/release_notes.md
index f7a01f8..0e57c7b 100644
--- a/docs/src/release_notes.md
+++ b/docs/src/release_notes.md
@@ -1,6 +1,9 @@
 
 # Release Notes
 
+## 0.4.x
+- Use StructArrays also for EDStore when building the model directly.
+
 
 ## 0.4.0
 ### New Functionality
diff --git a/src/Components.jl b/src/Components.jl
index b9c72e9..51e66fa 100644
--- a/src/Components.jl
+++ b/src/Components.jl
@@ -94,7 +94,7 @@ end
 Base.propertynames(oid::ObjectID) = tuple(fieldnames(ObjectID)...,:object)
 function register(p::ED) where ED
     collid = collectionID(ED)
-    store::Vector{ED} = EDStore_objects(ED, collid)
+    store = EDStore_objects(ED, collid)
     !iszero(p.index) && error("Registering an already registered MCParticle $p")
     last = lastindex(store)
     p = @set p.index = ObjectID{ED}(last, collid)
diff --git a/src/EDStore.jl b/src/EDStore.jl
index b99d653..547ef87 100644
--- a/src/EDStore.jl
+++ b/src/EDStore.jl
@@ -1,3 +1,5 @@
+using StructArrays
+
 export EDStore, getEDStore, initEDStore, assignEDStore, emptyEDStore, assignEDStore_relations, assignEDStore_vmembers
 
 mutable struct EDStore{ED <: POD}
@@ -8,13 +10,13 @@ mutable struct EDStore{ED <: POD}
 end
 
 function initialize!(store::EDStore{ED}) where ED <: POD
-    store.objects = ED[]
+    store.objects = StructArray(ED[])
     store.relations = Tuple(ObjectID{eltype(R)}[] for R in relations(ED))
     store.vmembers = Tuple(ObjectID{eltype(R)}[] for R in vmembers(ED))
 end
 
 function Base.empty!(store::EDStore{ED}) where ED <: POD
-    store.objects isa Vector && empty!(store.objects)
+    store.objects isa StructArray & empty!(store.objects)
     for (i,R) in enumerate(relations(ED))
         store.relations[i] isa Vector &&  empty!(store.relations[i])
     end
@@ -82,7 +84,7 @@ end
 function EDStore_objects(::Type{ED}, collid::UInt32=0x00000000) where ED
     store = getEDStore(ED, collid)
     if !isdefined(store, :objects)
-        store.objects = ED[]
+        store.objects = StructArray(ED[])
     end
     store.objects
 end