diff --git a/solutions/solutions.cabal b/solutions/solutions.cabal
index 0a8ed40..5f89b7d 100644
--- a/solutions/solutions.cabal
+++ b/solutions/solutions.cabal
@@ -861,7 +861,6 @@ executable sln_2021_24_sbv
   import:              day
   main-is:             2021/24_sbv.hs
   build-depends:       sbv, containers
-  buildable:           False
 
 executable sln_2021_25
   import:              day
@@ -1105,9 +1104,7 @@ executable sln_2023_23
 executable sln_2023_24
   import:              day
   main-is:             2023/24.hs
-  build-depends:       hmatrix, sbv ^>= 10.2
-  if impl(ghc >= 9.8)
-    buildable: False
+  build-depends:       hmatrix, sbv ^>= 11
 
 executable sln_2023_25
   import:              day
diff --git a/solutions/src/2024/13.hs b/solutions/src/2024/13.hs
index f6838d4..67931e6 100644
--- a/solutions/src/2024/13.hs
+++ b/solutions/src/2024/13.hs
@@ -85,14 +85,14 @@ single ax x
 -- <https://en.wikipedia.org/wiki/Diophantine_equation>
 colinear' :: Integer -> Integer -> Integer -> Integer
 colinear' ax bx x
-  | let (d, e, f) = integerGcde ax bx
-  , (h, 0) <- x `quotRem` d -- target x is a multiple of the gcd of the two button +x
-  , let a = e * h -- prototypical (but potentially negative) solution
-  , let b = f * h -- prototypical (but potentially negative) solution
-  , let u = ax `quot` d
-  , let v = - (bx `quot` d)
-  , let klo = a `divCeil` v
-  , let khi = b `div` u
+  | (d, e, f) <- integerGcde ax bx
+  , (h, 0)    <- x `quotRem` d -- target x is a multiple of the gcd of the two button +x
+  , a         <- e * h -- prototypical (but potentially negative) solution
+  , b         <- f * h -- prototypical (but potentially negative) solution
+  , u         <- ax `quot` d
+  , v         <- - (bx `quot` d)
+  , klo       <- a `divCeil` v
+  , khi       <- b `div` u
   , klo <= khi
   = minimum [3 * (a - k * v) + (b - k * u) | k <- [klo, khi]] -- the relation is linear so one of the extremes is the answer
   | otherwise = 0