diff --git a/src/core/utils/math.rs b/src/core/utils/math.rs
index f9d0de30..8c4b01be 100644
--- a/src/core/utils/math.rs
+++ b/src/core/utils/math.rs
@@ -7,32 +7,50 @@ use crate::{debug::type_name, err, Err, Error, Result};
 /// Checked arithmetic expression. Returns a Result<R, Error::Arithmetic>
 #[macro_export]
 macro_rules! checked {
-	($($input:tt)*) => {
-		$crate::utils::math::checked_ops!($($input)*)
+	($($input:tt)+) => {
+		$crate::utils::math::checked_ops!($($input)+)
 			.ok_or_else(|| $crate::err!(Arithmetic("operation overflowed or result invalid")))
-	}
+	};
 }
 
-/// in release-mode. Use for performance when the expression is obviously safe.
-/// The check remains in debug-mode for regression analysis.
+/// Checked arithmetic expression which panics on failure. This is for
+/// expressions which do not meet the threshold for validated! but the caller
+/// has no realistic expectation for error and no interest in cluttering the
+/// callsite with result handling from checked!.
+#[macro_export]
+macro_rules! expected {
+	($msg:literal, $($input:tt)+) => {
+		$crate::checked!($($input)+).expect($msg)
+	};
+
+	($($input:tt)+) => {
+		$crate::expected!("arithmetic expression expectation failure", $($input)+)
+	};
+}
+
+/// Unchecked arithmetic expression in release-mode. Use for performance when
+/// the expression is obviously safe. The check remains in debug-mode for
+/// regression analysis.
 #[cfg(not(debug_assertions))]
 #[macro_export]
 macro_rules! validated {
-	($($input:tt)*) => {
+	($($input:tt)+) => {
 		//#[allow(clippy::arithmetic_side_effects)] {
 		//Some($($input)*)
 		//	.ok_or_else(|| $crate::err!(Arithmetic("this error should never been seen")))
 		//}
 
 		//NOTE: remove me when stmt_expr_attributes is stable
-		$crate::checked!($($input)*)
-	}
+		$crate::expected!("validated arithmetic expression failed", $($input)+)
+	};
 }
 
+/// Checked arithmetic expression in debug-mode. Use for performance when
+/// the expression is obviously safe. The check is elided in release-mode.
 #[cfg(debug_assertions)]
 #[macro_export]
 macro_rules! validated {
-	($($input:tt)*) => { $crate::checked!($($input)*) }
+	($($input:tt)+) => { $crate::expected!($($input)+) }
 }
 
 /// Returns false if the exponential backoff has expired based on the inputs
diff --git a/src/service/rooms/auth_chain/mod.rs b/src/service/rooms/auth_chain/mod.rs
index 9a1e7e67..d0bc425f 100644
--- a/src/service/rooms/auth_chain/mod.rs
+++ b/src/service/rooms/auth_chain/mod.rs
@@ -66,7 +66,7 @@ impl Service {
 			.enumerate()
 		{
 			let bucket: usize = short.try_into()?;
-			let bucket: usize = validated!(bucket % NUM_BUCKETS)?;
+			let bucket: usize = validated!(bucket % NUM_BUCKETS);
 			buckets[bucket].insert((short, starting_events[i]));
 		}
 
diff --git a/src/service/rooms/timeline/mod.rs b/src/service/rooms/timeline/mod.rs
index 4f2352f8..04d9559d 100644
--- a/src/service/rooms/timeline/mod.rs
+++ b/src/service/rooms/timeline/mod.rs
@@ -1205,7 +1205,7 @@ impl Service {
 		let count = self.services.globals.next_count()?;
 		let mut pdu_id = shortroomid.to_be_bytes().to_vec();
 		pdu_id.extend_from_slice(&0_u64.to_be_bytes());
-		pdu_id.extend_from_slice(&(validated!(max - count)?).to_be_bytes());
+		pdu_id.extend_from_slice(&(validated!(max - count)).to_be_bytes());
 
 		// Insert pdu
 		self.db.prepend_backfill_pdu(&pdu_id, &event_id, &value)?;