diff --git a/CHANGELOG.md b/CHANGELOG.md
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,5 +1,8 @@
 # Revision history for less-arbitrary
 
+0.1.4.0 -- 2020-12-14
+* Added `HasCallStack` constraint to get better error locations.
+
 0.1.3.0 -- 2020-12-14
 * Added `suchThat`.
 
diff --git a/less-arbitrary.cabal b/less-arbitrary.cabal
--- a/less-arbitrary.cabal
+++ b/less-arbitrary.cabal
@@ -4,10 +4,10 @@
 --
 -- see: https://github.com/sol/hpack
 --
--- hash: 4ea65eec84a09bbf7d6249aa61d255e145ccba99f5e263d6bdc399a966156b71
+-- hash: 3086e65c4d07897ec67398597f75a2ce6165eb0b5419288640f12e83614b7c02
 
 name:           less-arbitrary
-version:        0.1.3.0
+version:        0.1.4.0
 synopsis:       Linear time testing with variant of Arbitrary class that always terminates.
 description:    Ever found non-terminating Arbitrary instance?
                 Ever wondered what would be a runtime cost of particular Arbitrary instance?
diff --git a/src/Test/LessArbitrary.hs b/src/Test/LessArbitrary.hs
--- a/src/Test/LessArbitrary.hs
+++ b/src/Test/LessArbitrary.hs
@@ -50,6 +50,7 @@
 import GHC.Generics as G
 import GHC.Generics as Generic
 import GHC.TypeLits
+import GHC.Stack
 import qualified Test.QuickCheck as QC
 import Data.Hashable
 
@@ -70,11 +71,14 @@
 
 -- ~\~ begin <<less-arbitrary.md|spend>>[0]
 spend :: Cost -> CostGen ()
-spend c = CostGen $ State.modify (-c+)
+spend c = do
+  CostGen $ State.modify (-c+)
+  checkBudget
 -- ~\~ end
 
 -- ~\~ begin <<less-arbitrary.md|budget>>[0]
-($$$?) :: CostGen a
+($$$?) :: HasCallStack
+       => CostGen a
        -> CostGen a
        -> CostGen a
 cheapVariants $$$? costlyVariants = do
@@ -83,13 +87,20 @@
      | budget > -10000      -> cheapVariants
      | otherwise            -> error $
        "Recursive structure with no loop breaker."
-
 -- ~\~ end
 -- ~\~ begin <<less-arbitrary.md|budget>>[1]
+checkBudget :: HasCallStack => CostGen ()
+checkBudget = do
+  budget <- CostGen State.get
+  if budget < -10000
+    then error "Recursive structure with no loop breaker."
+    else return ()
+-- ~\~ end
+-- ~\~ begin <<less-arbitrary.md|budget>>[2]
 currentBudget :: CostGen Cost
 currentBudget = CostGen State.get
 -- ~\~ end
--- ~\~ begin <<less-arbitrary.md|budget>>[2]
+-- ~\~ begin <<less-arbitrary.md|budget>>[3]
 -- unused: loop breaker message type name
 type family ShowType k where
   ShowType (D1 ('MetaData name _ _ _) _) = name
@@ -312,7 +323,8 @@
 forAll :: CostGen a -> (a -> CostGen b) -> CostGen b
 forAll gen prop = gen >>= prop
 
-oneof   :: [CostGen a] -> CostGen a
+oneof   :: HasCallStack
+        => [CostGen a] -> CostGen a
 oneof [] = error
            "LessArbitrary.oneof used with empty list"
 oneof gs = choose (0,length gs - 1) >>= (gs !!)
@@ -341,7 +353,8 @@
        cg `suchThat` pred
 -- ~\~ end
 -- ~\~ begin <<less-arbitrary.md|lifting-arbitrary>>[2]
-frequency :: [(Int, CostGen a)] -> CostGen a
+frequency   :: HasCallStack
+            => [(Int, CostGen a)] -> CostGen a
 frequency [] =
   error $ "LessArbitrary.frequency "
        ++ "used with empty list"