diff --git a/.github/workflows/CI.yml b/.github/workflows/CI.yml
index d0a3b706..2b40114e 100644
--- a/.github/workflows/CI.yml
+++ b/.github/workflows/CI.yml
@@ -44,7 +44,7 @@ jobs:
       fail-fast: false
       matrix:
         version:
-          - '1.8'
+          - '1.9'
         os:
           - ubuntu-latest
           - macOS-latest
diff --git a/Project.toml b/Project.toml
index 2a6af7d3..93fd65b8 100644
--- a/Project.toml
+++ b/Project.toml
@@ -34,4 +34,4 @@ SparseArrays = "1"
 StaticArrays = "1"
 SummationByPartsOperators = "0.5.41"
 TimerOutputs = "0.5.7"
-julia = "1.8"
+julia = "1.9"
diff --git a/README.md b/README.md
index c5829ce9..7615b6d1 100644
--- a/README.md
+++ b/README.md
@@ -23,7 +23,7 @@ A more detailed documentation can be found [online](https://JoshuaLampert.github
 ## Installation
 
 If you have not yet installed Julia, then you first need to [download Julia](https://julialang.org/downloads/). Please [follow the instructions for your operating system](https://julialang.org/downloads/platform/).
-DispersiveShallowWater.jl works with Julia v1.8 and newer. DispersiveShallowWater.jl is a registered Julia package. Therefore, you can install it by executing the following commands from the Julia REPL
+DispersiveShallowWater.jl works with Julia v1.9 and newer. DispersiveShallowWater.jl is a registered Julia package. Therefore, you can install it by executing the following commands from the Julia REPL
 ```julia
 julia> using Pkg
 
diff --git a/docs/src/index.md b/docs/src/index.md
index 121505b1..a66df7af 100644
--- a/docs/src/index.md
+++ b/docs/src/index.md
@@ -22,7 +22,7 @@ Fully discrete entropy-conservative methods can be obtained by using the [relaxa
 ## Installation
 
 If you have not yet installed Julia, then you first need to [download Julia](https://julialang.org/downloads/). Please [follow the instructions for your operating system](https://julialang.org/downloads/platform/).
-DispersiveShallowWater.jl works with Julia v1.8 and newer. DispersiveShallowWater.jl is a registered Julia package. Therefore, you can install it by executing the following commands from the Julia REPL
+DispersiveShallowWater.jl works with Julia v1.9 and newer. DispersiveShallowWater.jl is a registered Julia package. Therefore, you can install it by executing the following commands from the Julia REPL
 ```julia
 julia> using Pkg
 
diff --git a/src/callbacks_step/summary.jl b/src/callbacks_step/summary.jl
index 1a1fbdb0..8bb4b60a 100644
--- a/src/callbacks_step/summary.jl
+++ b/src/callbacks_step/summary.jl
@@ -1,9 +1,8 @@
 """
     SummaryCallback(io::IO = stdout)
 
-Create and return a callback that prints a human-readable summary of the simulation setup at the
-beginning of a simulation and then resets the timer. When the returned callback is executed
-directly, the current timer values are shown.
+Create and return a callback that resets the timer at the beginning of
+a simulation and prints the timer values at the end of the simulation.
 """
 struct SummaryCallback
     io::IO
@@ -12,12 +11,17 @@ struct SummaryCallback
         function initialize(cb, u, t, integrator)
             initialize_summary_callback(cb, u, t, integrator)
         end
+        # At the end of the simulation, the timer is printed
+        function finalize(cb, u, t, integrator)
+            finalize_summary_callback(cb, u, t, integrator)
+        end
         summary_callback = new(io)
-        # SummaryCallback is called at end of simulation
-        condition = (u, t, integrator) -> isfinished(integrator)
+        # SummaryCallback is never called during the simulation
+        condition = (u, t, integrator) -> false
         DiscreteCallback(condition, summary_callback,
                          save_positions = (false, false),
-                         initialize = initialize)
+                         initialize = initialize,
+                         finalize = finalize)
     end
 end
 
@@ -32,22 +36,14 @@ function initialize_summary_callback(cb::DiscreteCallback, u, t, integrator)
     return nothing
 end
 
-function (cb::SummaryCallback)(integrator)
-    u_modified!(integrator, false)
-    cb()
-end
+# the summary callback does nothing when called accidentally
+(cb::SummaryCallback)(integrator) = u_modified!(integrator, false)
 
-function (summary_callback::SummaryCallback)()
-    io = summary_callback.io
+function finalize_summary_callback(cb::DiscreteCallback, u, t, integrator)
+    io = cb.affect!.io
     TimerOutputs.complement!(timer())
     print_timer(io, timer(), title = "DispersiveSWE",
                 allocations = true, linechars = :unicode, compact = false)
     println(io)
     return nothing
 end
-
-# Allow calling the callback explicitly
-function (cb::DiscreteCallback{Condition, Affect!})() where {Condition,
-                                                             Affect! <: SummaryCallback}
-    cb.affect!()
-end
diff --git a/test/test_unit.jl b/test/test_unit.jl
index 782f9dfd..d00a7228 100644
--- a/test/test_unit.jl
+++ b/test/test_unit.jl
@@ -218,7 +218,6 @@ using SparseArrays: sparse, SparseMatrixCSC
         summary_callback = SummaryCallback()
         @test_nowarn print(summary_callback)
         @test_nowarn display(summary_callback)
-        @test_nowarn summary_callback()
     end
 
     @testset "util" begin