diff --git a/frame/support/procedural/src/pallet/parse/call.rs b/frame/support/procedural/src/pallet/parse/call.rs
index 9620038edfd6d..3af3225484fae 100644
--- a/frame/support/procedural/src/pallet/parse/call.rs
+++ b/frame/support/procedural/src/pallet/parse/call.rs
@@ -93,6 +93,10 @@ impl syn::parse::Parse for FunctionAttr {
 			let call_index_content;
 			syn::parenthesized!(call_index_content in content);
 			let index = call_index_content.parse::<syn::LitInt>()?;
+			if !index.suffix().is_empty() {
+				let msg = "Number literal must not have a suffix";
+				return Err(syn::Error::new(index.span(), msg))
+			}
 			Ok(FunctionAttr::CallIndex(index.base10_parse()?))
 		} else {
 			Err(lookahead.error())
diff --git a/frame/support/test/tests/pallet_ui/call_index_has_suffix.rs b/frame/support/test/tests/pallet_ui/call_index_has_suffix.rs
new file mode 100644
index 0000000000000..abe4dc199bf51
--- /dev/null
+++ b/frame/support/test/tests/pallet_ui/call_index_has_suffix.rs
@@ -0,0 +1,20 @@
+#[frame_support::pallet]
+mod pallet {
+	use frame_support::pallet_prelude::DispatchResultWithPostInfo;
+	use frame_system::pallet_prelude::OriginFor;
+
+	#[pallet::config]
+	pub trait Config: frame_system::Config {}
+
+	#[pallet::pallet]
+	pub struct Pallet<T>(core::marker::PhantomData<T>);
+
+	#[pallet::call]
+	impl<T: Config> Pallet<T> {
+        #[pallet::call_index(0something)]
+		pub fn foo(origin: OriginFor<T>) -> DispatchResultWithPostInfo {}
+	}
+}
+
+fn main() {
+}
diff --git a/frame/support/test/tests/pallet_ui/call_index_has_suffix.stderr b/frame/support/test/tests/pallet_ui/call_index_has_suffix.stderr
new file mode 100644
index 0000000000000..2f4cead6cf70c
--- /dev/null
+++ b/frame/support/test/tests/pallet_ui/call_index_has_suffix.stderr
@@ -0,0 +1,5 @@
+error: Number literal must not have a suffix
+  --> tests/pallet_ui/call_index_has_suffix.rs:14:30
+   |
+14 |         #[pallet::call_index(0something)]
+   |                              ^^^^^^^^^^
diff --git a/frame/support/test/tests/pallet_ui/weight_argument_has_suffix.rs b/frame/support/test/tests/pallet_ui/weight_argument_has_suffix.rs
new file mode 100644
index 0000000000000..99195d21be62e
--- /dev/null
+++ b/frame/support/test/tests/pallet_ui/weight_argument_has_suffix.rs
@@ -0,0 +1,21 @@
+#[frame_support::pallet]
+mod pallet {
+	use frame_support::pallet_prelude::DispatchResultWithPostInfo;
+	use frame_system::pallet_prelude::OriginFor;
+
+	#[pallet::config]
+	pub trait Config: frame_system::Config {}
+
+	#[pallet::pallet]
+	pub struct Pallet<T>(core::marker::PhantomData<T>);
+
+	#[pallet::call]
+	impl<T: Config> Pallet<T> {
+		#[pallet::call_index(0)]
+        #[pallet::weight(10_000something)]
+		pub fn foo(origin: OriginFor<T>) -> DispatchResultWithPostInfo { Ok(().into()) }
+	}
+}
+
+fn main() {
+}
diff --git a/frame/support/test/tests/pallet_ui/weight_argument_has_suffix.stderr b/frame/support/test/tests/pallet_ui/weight_argument_has_suffix.stderr
new file mode 100644
index 0000000000000..c9b2010f88bb3
--- /dev/null
+++ b/frame/support/test/tests/pallet_ui/weight_argument_has_suffix.stderr
@@ -0,0 +1,41 @@
+error: invalid suffix `something` for number literal
+  --> tests/pallet_ui/weight_argument_has_suffix.rs:15:26
+   |
+15 |         #[pallet::weight(10_000something)]
+   |                          ^^^^^^^^^^^^^^^ invalid suffix `something`
+   |
+   = help: the suffix must be one of the numeric types (`u32`, `isize`, `f32`, etc.)
+
+error[E0308]: mismatched types
+   --> tests/pallet_ui/weight_argument_has_suffix.rs:12:12
+    |
+12  |     #[pallet::call]
+    |               ^^^^
+    |               |
+    |               expected trait `frame_support::dispatch::ClassifyDispatch`, found trait `frame_support::dispatch::WeighData`
+    |               arguments to this function are incorrect
+    |
+    = note: expected reference `&dyn frame_support::dispatch::ClassifyDispatch<()>`
+               found reference `&dyn frame_support::dispatch::WeighData<()>`
+note: associated function defined here
+   --> $WORKSPACE/frame/support/src/dispatch.rs
+    |
+    |     fn classify_dispatch(&self, target: T) -> DispatchClass;
+    |        ^^^^^^^^^^^^^^^^^
+
+error[E0308]: mismatched types
+   --> tests/pallet_ui/weight_argument_has_suffix.rs:12:12
+    |
+12  |     #[pallet::call]
+    |               ^^^^
+    |               |
+    |               expected trait `frame_support::dispatch::PaysFee`, found trait `frame_support::dispatch::WeighData`
+    |               arguments to this function are incorrect
+    |
+    = note: expected reference `&dyn frame_support::dispatch::PaysFee<()>`
+               found reference `&dyn frame_support::dispatch::WeighData<()>`
+note: associated function defined here
+   --> $WORKSPACE/frame/support/src/dispatch.rs
+    |
+    |     fn pays_fee(&self, _target: T) -> Pays;
+    |        ^^^^^^^^