diff --git a/include/initialsol/simple.hpp b/include/initialsol/simple.hpp
index e96f89a49..e4d98d9fe 100644
--- a/include/initialsol/simple.hpp
+++ b/include/initialsol/simple.hpp
@@ -55,7 +55,7 @@ class Initial_solution : public problem::Solution {
      */
     void one_truck_all_orders();
 
-    void do_while_foo(int kind);
+    void do_while_foo(Initials_code);
 
     void do_while_feasible(
         problem::Vehicle_pickDeliver& truck,
diff --git a/src/initialsol/simple.cpp b/src/initialsol/simple.cpp
index 96394b3db..abcf572c7 100644
--- a/src/initialsol/simple.cpp
+++ b/src/initialsol/simple.cpp
@@ -52,7 +52,7 @@ Initial_solution::Initial_solution(
     unassigned(m_orders.size()),
     assigned() {
         invariant();
-        pgassert(kind >= 0 && kind <= OneDepot);
+        pgassert(kind >= OneTruck && kind <= OneDepot);
 
         switch (kind) {
             case OneTruck:
@@ -74,9 +74,10 @@ Initial_solution::Initial_solution(
 }
 
 void
-Initial_solution::do_while_foo(int kind) {
+Initial_solution::do_while_foo(Initials_code kind) {
     invariant();
-    pgassert(kind > 0 && kind <= OneDepot);
+    pgassert(kind != OneTruck);
+    pgassert(kind > OneTruck && kind <= OneDepot);
 
     Identifiers<size_t> notused;