diff --git a/vm/state.go b/vm/state.go
index ba1ed6b..cfbbd91 100644
--- a/vm/state.go
+++ b/vm/state.go
@@ -79,11 +79,11 @@ func (state *State) processInstruction() {
 		state.running = false
 	}
 
-	if state.functionIndex < 0 || state.functionIndex >= int64(len(state.program.Functions)) {
-		state.ret()
-	}
+	for state.functionIndex < 0 ||
+		state.functionIndex >= int64(len(state.program.Functions)) ||
+		state.instructionIndex < 0 ||
+		state.instructionIndex >= int64(len(state.function().Instructions)) {
 
-	if state.instructionIndex < 0 || state.instructionIndex >= int64(len(fnc.Instructions)) {
 		state.ret()
 	}
 }