diff --git a/src/CodeInterpreter.hh b/src/CodeInterpreter.hh
index 832c6e855b53b95b1a3c01de2d1417348d166142..5045f5778e179799af5c4b872c3caced80fbf41f 100644
--- a/src/CodeInterpreter.hh
+++ b/src/CodeInterpreter.hh
@@ -1267,7 +1267,7 @@ class FNUMEXPR_ : public TagWithOneArgument<ExpressionType>
 private:
   unsigned int equation;
   uint16_t dvariable1, dvariable2, dvariable3;
-  int8_t lag1, lag2, lag3;
+  int lag1, lag2, lag3;
 public:
   inline
   FNUMEXPR_() : TagWithOneArgument<ExpressionType>::TagWithOneArgument{Tags::FNUMEXPR}
@@ -1294,7 +1294,7 @@ public:
     TagWithOneArgument<ExpressionType>::TagWithOneArgument{Tags::FNUMEXPR, expression_type},
     equation{equation_arg},
     dvariable1{static_cast<uint16_t>(dvariable1_arg)}, dvariable2{0}, dvariable3{0},
-    lag1{static_cast<int8_t>(lag1_arg)}, lag2{0}, lag3{0}
+    lag1{lag1_arg}, lag2{0}, lag3{0}
   {
   };
   inline
@@ -1314,8 +1314,8 @@ public:
     dvariable1{static_cast<uint16_t>(dvariable1_arg)},
     dvariable2{static_cast<uint16_t>(dvariable2_arg)},
     dvariable3{0},
-    lag1{static_cast<int8_t>(lag1_arg)},
-    lag2{static_cast<int8_t>(lag2_arg)},
+    lag1{lag1_arg},
+    lag2{lag2_arg},
     lag3{0}
   {
   };
@@ -1336,9 +1336,9 @@ public:
     dvariable1{static_cast<uint16_t>(dvariable1_arg)},
     dvariable2{static_cast<uint16_t>(dvariable2_arg)},
     dvariable3{static_cast<uint16_t>(dvariable3_arg)},
-    lag1{static_cast<int8_t>(lag1_arg)},
-    lag2{static_cast<int8_t>(lag2_arg)},
-    lag3{static_cast<int8_t>(lag3_arg)}
+    lag1{lag1_arg},
+    lag2{lag2_arg},
+    lag3{lag3_arg}
   {
   };
   inline ExpressionType