diff --git a/CHANGELOG.md b/CHANGELOG.md
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,3 +1,7 @@
+#### 0.10.4 (2026-05-18)
+
+* Bump upper bound of QuickCheck for 2.18.
+
 #### 0.10.3 (2026-02-12)
 
 * Bump upper bound of QuickCheck for 2.17.
diff --git a/quickcheck-state-machine.cabal b/quickcheck-state-machine.cabal
--- a/quickcheck-state-machine.cabal
+++ b/quickcheck-state-machine.cabal
@@ -1,6 +1,6 @@
 cabal-version:   3.0
 name:            quickcheck-state-machine
-version:         0.10.3
+version:         0.10.4
 synopsis:        Test monadic programs using state machine based models
 description:
   See README at <https://github.com/stevana/quickcheck-state-machine#readme>
@@ -23,7 +23,7 @@
   README.md
 
 tested-with:
-  GHC ==8.8.4 || ==8.10.7 || ==9.2.8 || ==9.4.8 || ==9.6.5 || ==9.8.2
+  GHC ==8.8.4 || ==8.10.7 || ==9.2.8 || ==9.4.8 || ==9.6.5 || ==9.8.2 || ==9.12.2
 
 -- Due to `tree-diff` being `GPL`, this library makes use of an interface
 -- (@CanDiff@) to diff models. This can be implemented with the vendored
@@ -74,7 +74,7 @@
     , pretty-show                  >=1.6.16      && <1.11
     , prettyprinter                ^>=1.7.1
     , prettyprinter-ansi-terminal  ^>=1.1.3
-    , QuickCheck                   >=2.12        && <2.18
+    , QuickCheck                   >=2.12        && <2.19
     , random                       >=1.1         && <1.4
     , sop-core                     >=0.5.0.2     && <0.6
     , split                        >=0.2.3.5     && <0.3