diff --git a/Cargo.lock b/Cargo.lock
index ff3b50e..caec350 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -77,7 +77,7 @@ dependencies = [
 
 [[package]]
 name = "onlyargs_derive"
-version = "0.1.3"
+version = "0.1.4"
 dependencies = [
  "myn",
  "onlyargs",
diff --git a/onlyargs_derive/Cargo.toml b/onlyargs_derive/Cargo.toml
index 7f24ad9..ee64bb8 100644
--- a/onlyargs_derive/Cargo.toml
+++ b/onlyargs_derive/Cargo.toml
@@ -1,7 +1,7 @@
 [package]
 name = "onlyargs_derive"
 description = "Obsessively tiny argument parsing derive macro"
-version = "0.1.3"
+version = "0.1.4"
 authors = ["Jay Oster <jay@kodewerx.org>"]
 repository = "https://github.com/parasyte/onlyargs"
 edition = "2021"
diff --git a/onlyargs_derive/compile_tests/compiler.rs b/onlyargs_derive/compile_tests/compiler.rs
index e486e4d..740489c 100644
--- a/onlyargs_derive/compile_tests/compiler.rs
+++ b/onlyargs_derive/compile_tests/compiler.rs
@@ -28,7 +28,9 @@ fn compile_tests() {
     t.pass("compile_tests/positional_pathbuf.rs");
     t.pass("compile_tests/positional_string.rs");
     t.pass("compile_tests/positional_u8.rs");
+    t.pass("compile_tests/positional_u128.rs");
     t.pass("compile_tests/positional_usize.rs");
+    t.compile_fail("compile_tests/conflicting_positional.rs");
 
     t.pass("compile_tests/empty.rs");
     t.pass("compile_tests/optional.rs");
diff --git a/onlyargs_derive/compile_tests/conflicting_positional.rs b/onlyargs_derive/compile_tests/conflicting_positional.rs
new file mode 100644
index 0000000..3b9f2b2
--- /dev/null
+++ b/onlyargs_derive/compile_tests/conflicting_positional.rs
@@ -0,0 +1,7 @@
+#[derive(Debug, onlyargs_derive::OnlyArgs)]
+struct Args {
+    rest: Vec<String>,
+    more: Vec<String>,
+}
+
+fn main() {}
diff --git a/onlyargs_derive/compile_tests/conflicting_positional.stderr b/onlyargs_derive/compile_tests/conflicting_positional.stderr
new file mode 100644
index 0000000..f385a2c
--- /dev/null
+++ b/onlyargs_derive/compile_tests/conflicting_positional.stderr
@@ -0,0 +1,5 @@
+error: Positional arguments can only be specified once.
+ --> compile_tests/conflicting_positional.rs:4:5
+  |
+4 |     more: Vec<String>,
+  |     ^^^^