diff --git a/lightning/src/routing/scoring.rs b/lightning/src/routing/scoring.rs
index 06bc9704d13..313529ec59b 100644
--- a/lightning/src/routing/scoring.rs
+++ b/lightning/src/routing/scoring.rs
@@ -1195,7 +1195,7 @@ fn success_probability(
 			const BILLIONISH: f64 = 1024.0 * 1024.0 * 1024.0 * 64.0;
 			let numerator = (num * BILLIONISH) as u64 + 1;
 			let denominator = (den * BILLIONISH) as u64 + 1;
-			debug_assert!(numerator <= 1 << 30, "Got large numerator ({}) from float {} (min {}, amt {}, max {}).", numerator, num, min, amount, max);
+			debug_assert!(numerator <= 1 << 30, "Got large numerator ({}) from float {} (min {}/{}/{}, amt {}/{}/{}, max {}/{}/{}).", numerator, num, min, min_pow, min_v, amount, amt_pow, amt_v, max, min_pow, min_v);
 			debug_assert!(denominator <= 1 << 30, "Got large denominator ({}) from float {} (min {}, amt {}, max {}).", denominator, den, min, amount, max);
 			(numerator, denominator)
 		};