diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index c736569e..f62ff665 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -36,18 +36,19 @@ jobs:
           - x64
         julia_version:
           - '1.10'
-          - '1.11'
+          - '1.12'
         t8code_version:
           - '3.0.1'
         include:
           - os: ubuntu-latest
             test_type: coverage
             arch: x64
-            julia_version: '1.11'
+            julia_version: '1.12'
             t8code_version: '3.0.1'
     env:
-      # Necessary for HDF5 to play nice with Julia
-      LD_PRELOAD: /lib/x86_64-linux-gnu/libcurl.so.4
+      # Necessary for HDF5 to play nice with Julia 1.10
+      # https://docs.github.com/en/actions/reference/workflows-and-actions/expressions#example
+      LD_PRELOAD: ${{ matrix.julia_version == '1.10' && '/lib/x86_64-linux-gnu/libcurl.so.4' || '' }}
       # Necessary such that libtrixi will not use its own default for the depot path
       JULIA_DEPOT_PATH: ~/.julia
     steps:
@@ -115,22 +116,27 @@ jobs:
       - name: Configure (test_type == 'regular')
         if: ${{ matrix.test_type == 'regular' }}
         run: |
+          # remove once https://github.com/JuliaLang/julia/pull/57681 is in the release
+          C_FLAGS=${{ matrix.julia_version == '1.12' && '-Wno-error=unused-parameter' || '' }}
           mkdir build
           cd build
           cmake .. -DCMAKE_INSTALL_PREFIX=../install \
                    -DCMAKE_BUILD_TYPE=Release \
+                   -DCMAKE_C_FLAGS="${C_FLAGS}" \
                    -DT8CODE_ROOT=$PWD/../t8code-local/prefix \
                    -DENABLE_TESTING=ON -DJULIA_PROJECT_PATH=../libtrixi-julia
 
       - name: Configure (test_type == 'coverage')
         if: ${{ matrix.test_type == 'coverage' }}
         run: |
+          # remove once https://github.com/JuliaLang/julia/pull/57681 is in the release
+          C_FLAGS=${{ matrix.julia_version == '1.12' && '-Wno-error=unused-parameter' || '' }}
           mkdir build
           cd build
           cmake .. -DCMAKE_INSTALL_PREFIX=../install \
                    -DCMAKE_BUILD_TYPE=Debug \
                    -DT8CODE_ROOT=$PWD/../t8code-local/prefix \
-                   -DCMAKE_C_FLAGS="-cpp --coverage -O0" \
+                   -DCMAKE_C_FLAGS="-cpp --coverage -O0 ${C_FLAGS}" \
                    -DCMAKE_Fortran_FLAGS="-cpp --coverage -O0" \
                    -DCMAKE_EXE_LINKER_FLAGS="--coverage" \
                    -DCMAKE_SHARED_LINKER_FLAGS="--coverage" \
@@ -205,7 +211,7 @@ jobs:
         if: ${{ matrix.test_type == 'package-compiler' }}
         run: |
           cd build
-          make -j2
+          make
           du -hL ./prefix-pc/lib/libtrixi.so
 
       - name: Test external CMake project
@@ -313,6 +319,8 @@ jobs:
           cd build/test/c
           ctest -V
         env:
+          # This seems to fix stalling tests with Julia 1.12
+          JULIA_NUM_THREADS: 1
           LIBTRIXI_DEBUG: all
           GTEST_COLOR: 'yes'
 
diff --git a/CMakeLists.txt b/CMakeLists.txt
index 5376e94d..845a16e0 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -99,6 +99,7 @@ if( USE_PACKAGE_COMPILER )
                         COMMENT "Building ${PROJECT_NAME} with PackageCompiler.jl..."
                         COMMAND ${JULIA_EXECUTABLE}
                                 --project=${CMAKE_SOURCE_DIR}/LibTrixi.jl/lib
+                                --threads=1
                                 ${CMAKE_SOURCE_DIR}/LibTrixi.jl/lib/build.jl
                                 ${JULIA_PROJECT_PATH}
                                 ${CMAKE_BINARY_DIR}/prefix-pc
diff --git a/LibTrixi.jl/src/api_jl.jl b/LibTrixi.jl/src/api_jl.jl
index 637ab34c..1c9c5d99 100644
--- a/LibTrixi.jl/src/api_jl.jl
+++ b/LibTrixi.jl/src/api_jl.jl
@@ -8,8 +8,7 @@ function trixi_initialize_simulation_jl(filename)
 
     # Initialize simulation state
     # Note: we need `invokelatest` here since the function is dynamically upon `include`
-    # Note: `invokelatest` is not exported until Julia v1.9, thus we call it through `Base`
-    simstate = Base.invokelatest(Main.init_simstate)
+    simstate = @invokelatest Main.init_simstate()
 
     if show_debug_output()
         println("Simulation state initialized")