diff --git a/interpreter/src/ir.rs b/interpreter/src/ir.rs
index 0a9b889..c762e7f 100644
--- a/interpreter/src/ir.rs
+++ b/interpreter/src/ir.rs
@@ -77,7 +77,7 @@ pub enum Instruction {
     StoreRecord(BinaryArg),
     IntrinsicCall(CallArgs),
     OutputCall(OutputCallArgs),
-    UserCall(IndCallArgs),
+    UserCall(CallArgs),
     IndirectCall(CallArgs),
     Jump(JumpArg),
     Return(RetArg),
@@ -94,9 +94,9 @@ pub type MemArg = (Reg, NonLocal);
 pub type JumpArg = Label;
 pub type RetArg = MaybeImm;
 pub type BranchArg = (MaybeImm, Label, Label);
-pub type CallArgs = (Reg, Reg, NonLocal);
+pub type CallArgs = (Reg, Reg, Reg, NonLocal);
 pub type OutputCallArgs = (Reg, Reg, Command, Option<Redirection>);
-pub type IndCallArgs = (Reg, Reg, Reg);
+pub type IndCallArgs = (Reg, Reg, Reg, Reg);
 
 #[repr(u8)]
 #[derive(Clone, Copy, Debug)]
@@ -195,8 +195,9 @@ impl Display for Instruction {
             Self::Return(src) => {
                 write!(f, "{op} {src}")
             }
-            Self::IntrinsicCall((dest, code, args)) | Self::IndirectCall((dest, code, args)) => {
-                write!(f, "{dest} <- {op} {code}, {args}")
+            Self::IntrinsicCall((dest, start, end, fun))
+            | Self::IndirectCall((dest, start, end, fun)) => {
+                write!(f, "{dest} <- {op} {fun}, {start}..{end}")
             }
             Self::OutputCall((start, end, call, Some(redir))) => {
                 write!(f, "{call}{redir:?} {start}..{end}")
@@ -204,8 +205,8 @@ impl Display for Instruction {
             Self::OutputCall((start, end, call, None)) => {
                 write!(f, "{call} {start}..{end}")
             }
-            Self::UserCall((dest, src, args)) => {
-                write!(f, "{dest} <- {op} {src}, {args}")
+            Self::UserCall((dest, start, end, fun)) => {
+                write!(f, "{dest} <- {op} {fun}, {start}..{end}")
             }
         }
     }
diff --git a/interpreter/src/vm.rs b/interpreter/src/vm.rs
index e0cfa58..af1c5d0 100644
--- a/interpreter/src/vm.rs
+++ b/interpreter/src/vm.rs
@@ -213,12 +213,12 @@ impl Interpreter<'_> {
                 Instruction::StoreRecord(_) => todo!(),
                 Instruction::StoreBuiltinScalar((_dest, _imm, _src)) => todo!(),
                 Instruction::StoreBuiltinArray((_dest, _src, _start, _end)) => todo!(),
-                Instruction::IntrinsicCall((_dest, _code, _args)) => todo!(),
+                Instruction::IntrinsicCall((_dest, _start, _end, _fun)) => todo!(),
                 Instruction::OutputCall((start, end, fun, redir)) => {
                     self.intrinsic_print(start, end, fun, redir);
                 }
-                Instruction::UserCall((_dest, _code, _args)) => todo!(),
-                Instruction::IndirectCall((_dest, _code, _args)) => todo!(),
+                Instruction::UserCall((_dest, _start, _end, _fun)) => todo!(),
+                Instruction::IndirectCall((_dest, _start, _end, _fun)) => todo!(),
                 Instruction::Jump(Label(label)) => {
                     self.program_counter = label as _;
                     continue;