diff --git a/docs/Project.toml b/docs/Project.toml
index 9fc974d6f38..ffa86e0b9f7 100644
--- a/docs/Project.toml
+++ b/docs/Project.toml
@@ -13,7 +13,7 @@ Trixi2Vtk = "bc1476a1-1ca6-4cc3-950b-c312b255ff95"
 
 [compat]
 CairoMakie = "0.6, 0.7, 0.8, 0.9, 0.10"
-Documenter = "0.27"
+Documenter = "1"
 ForwardDiff = "0.10"
 HOHQMesh = "0.1, 0.2"
 LaTeXStrings = "1.2"
diff --git a/docs/make.jl b/docs/make.jl
index f882fcf1219..df8ac04be12 100644
--- a/docs/make.jl
+++ b/docs/make.jl
@@ -77,7 +77,7 @@ makedocs(
     # Specify modules for which docstrings should be shown
     modules = [Trixi, Trixi2Vtk],
     # Set sitename to Trixi.jl
-    sitename="Trixi.jl",
+    sitename = "Trixi.jl",
     # Provide additional formatting options
     format = Documenter.HTML(
         # Disable pretty URLs during manual testing
@@ -85,7 +85,8 @@ makedocs(
         # Explicitly add favicon as asset
         assets = ["assets/favicon.ico"],
         # Set canonical URL to GitHub pages URL
-        canonical = "https://trixi-framework.github.io/Trixi.jl/stable"
+        canonical = "https://trixi-framework.github.io/Trixi.jl/stable",
+        size_threshold_ignore = ["reference-trixi.md"]
     ),
     # Explicitly specify documentation structure
     pages = [
@@ -124,9 +125,8 @@ makedocs(
         "Authors" => "authors.md",
         "Contributing" => "contributing.md",
         "Code of Conduct" => "code_of_conduct.md",
-        "License" => "license.md"
-    ],
-    strict = true # to make the GitHub action fail when doctests fail, see https://github.com/neuropsychology/Psycho.jl/issues/34
+        "License" => "license.md",
+    ]
 )
 
 deploydocs(
diff --git a/src/solvers/dgsem_unstructured/dg_2d.jl b/src/solvers/dgsem_unstructured/dg_2d.jl
index 7b8dafdddd2..b12a96c4c31 100644
--- a/src/solvers/dgsem_unstructured/dg_2d.jl
+++ b/src/solvers/dgsem_unstructured/dg_2d.jl
@@ -357,9 +357,9 @@ function calc_boundary_flux_by_type!(cache, t, BCs::Tuple{}, BC_indices::Tuple{}
     nothing
 end
 
-function calc_boundary_flux!(cache, t, boundary_condition, boundary_indexing,
+function calc_boundary_flux!(cache, t, boundary_condition::BC, boundary_indexing,
                              mesh::UnstructuredMesh2D, equations,
-                             surface_integral, dg::DG)
+                             surface_integral, dg::DG) where {BC}
     @unpack surface_flux_values = cache.elements
     @unpack element_id, element_side_id = cache.boundaries
 
diff --git a/src/time_integration/methods_SSP.jl b/src/time_integration/methods_SSP.jl
index 8ecad69748b..a0ed889968a 100644
--- a/src/time_integration/methods_SSP.jl
+++ b/src/time_integration/methods_SSP.jl
@@ -24,14 +24,16 @@ The third-order SSP Runge-Kutta method of Shu and Osher.
     This is an experimental feature and may change in future releases.
 """
 struct SimpleSSPRK33{StageCallbacks} <: SimpleAlgorithmSSP
-    a::SVector{3, Float64}
-    b::SVector{3, Float64}
+    numerator_a::SVector{3, Float64}
+    numerator_b::SVector{3, Float64}
+    denominator::SVector{3, Float64}
     c::SVector{3, Float64}
     stage_callbacks::StageCallbacks
 
     function SimpleSSPRK33(; stage_callbacks = ())
-        a = SVector(0.0, 3 / 4, 1 / 3)
-        b = SVector(1.0, 1 / 4, 2 / 3)
+        numerator_a = SVector(0.0, 3.0, 1.0) # a = numerator_a / denominator
+        numerator_b = SVector(1.0, 1.0, 2.0) # b = numerator_b / denominator
+        denominator = SVector(1.0, 4.0, 3.0)
         c = SVector(0.0, 1.0, 1 / 2)
 
         # Butcher tableau
@@ -42,7 +44,8 @@ struct SimpleSSPRK33{StageCallbacks} <: SimpleAlgorithmSSP
         # --------------------
         #   b | 1/6  1/6  2/3
 
-        new{typeof(stage_callbacks)}(a, b, c, stage_callbacks)
+        new{typeof(stage_callbacks)}(numerator_a, numerator_b, denominator, c,
+                                     stage_callbacks)
     end
 end
 
@@ -166,7 +169,9 @@ function solve!(integrator::SimpleIntegratorSSP)
             end
 
             # perform convex combination
-            @. integrator.u = alg.a[stage] * integrator.r0 + alg.b[stage] * integrator.u
+            @. integrator.u = (alg.numerator_a[stage] * integrator.r0 +
+                               alg.numerator_b[stage] * integrator.u) /
+                              alg.denominator[stage]
         end
 
         integrator.iter += 1
diff --git a/test/test_threaded.jl b/test/test_threaded.jl
index 2337d73f30a..b13b5d0f5fc 100644
--- a/test/test_threaded.jl
+++ b/test/test_threaded.jl
@@ -312,11 +312,7 @@ Trixi.mpi_isroot() && isdir(outdir) && rm(outdir, recursive=true)
         t = sol.t[end]
         u_ode = sol.u[end]
         du_ode = similar(u_ode)
-        if (Threads.nthreads() < 2) || (VERSION < v"1.9")
-          @test (@allocated Trixi.rhs!(du_ode, u_ode, semi, t)) < 5000
-        else
-          @test_broken (@allocated Trixi.rhs!(du_ode, u_ode, semi, t)) < 5000
-        end
+        @test (@allocated Trixi.rhs!(du_ode, u_ode, semi, t)) < 5000
       end
     end