diff --git a/src/program.rs b/src/program.rs
index 0636f64f..e40998a5 100644
--- a/src/program.rs
+++ b/src/program.rs
@@ -317,8 +317,8 @@ impl<C: ContextObject> BuiltinProgram<C> {
     pub fn register_function(
         &mut self,
         name: &str,
-        value: BuiltinFunction<C>,
         dense_key: u32,
+        value: BuiltinFunction<C>,
     ) -> Result<(), ElfError> {
         self.sparse_registry.register_function_hashed(name, value)?;
         self.dense_registry
diff --git a/tests/verifier.rs b/tests/verifier.rs
index 61c74899..dc846c58 100644
--- a/tests/verifier.rs
+++ b/tests/verifier.rs
@@ -373,7 +373,7 @@ fn test_verifier_known_syscall() {
 
     let mut loader = BuiltinProgram::new_loader_with_dense_registration(Config::default());
     loader
-        .register_function("my_syscall", syscalls::SyscallString::vm, 2)
+        .register_function("my_syscall", 2, syscalls::SyscallString::vm)
         .unwrap();
     let executable = Executable::<TestContextObject>::from_text_bytes(
         prog,