diff --git a/.github/workflows/CI.yml b/.github/workflows/CI.yml
index 3e39db0..401e807 100644
--- a/.github/workflows/CI.yml
+++ b/.github/workflows/CI.yml
@@ -28,6 +28,9 @@ jobs:
         os:
           - ubuntu-latest
         include:
+          - julia-version: 1
+            os: ubuntu-latest
+            cxx-coverage: true
           # Add a few windows and macOS jobs (not too many, the number we can run in parallel is limited)
           - julia-version: lts
             os: macOS-latest
@@ -53,6 +56,8 @@ jobs:
           update_packager_index: false
       - name: "Build package"
         uses: julia-actions/julia-buildpkg@v1
+        env:
+          NORMALIZ_JL_CXX_COVERAGE: ${{ matrix.cxx-coverage == true && 'true' || 'false' }}
       - name: "Run tests"
         uses: julia-actions/julia-runtest@v1
         with:
@@ -70,11 +75,30 @@ jobs:
 
       - name: "Process code coverage"
         uses: julia-actions/julia-processcoverage@v1
+      - name: "Install gcovr"
+        if: ${{ matrix.cxx-coverage == true }}
+        run: python -m pip install gcovr
+      - name: "Process C++ coverage"
+        if: ${{ matrix.cxx-coverage == true }}
+        run: |
+          gcovr --version
+          gcovr \
+            --root "$PWD" \
+            --filter deps/src/normaliz.cpp \
+            --gcov-object-directory deps/src/build \
+            --exclude-throw-branches \
+            --xml-pretty \
+            --output coverage.xml \
+            --print-summary
       - name: "Upload coverage data to Codecov"
         continue-on-error: true
         uses: codecov/codecov-action@v6
         with:
           token: ${{ secrets.CODECOV_TOKEN }}
+          files: coverage.xml
+          disable_search: true
+          fail_ci_if_error: true
+          verbose: true
 
   docs:
     name: Documentation
diff --git a/deps/build.jl b/deps/build.jl
index 64829f2..9f0af59 100644
--- a/deps/build.jl
+++ b/deps/build.jl
@@ -6,6 +6,9 @@ using normaliz_jll
 
 # Parse some basic command-line arguments
 const verbose = "--verbose" in ARGS
+const cxx_coverage =
+    lowercase(get(ENV, "NORMALIZ_JL_CXX_COVERAGE", "false")) in
+    ("1", "true", "yes", "on")
 
 jlcxx_cmake_dir = joinpath(CxxWrap.prefix_path(), "lib", "cmake", "JlCxx")
 julia_exec = joinpath(Sys.BINDIR, Base.julia_exename())
@@ -48,7 +51,8 @@ CMake_jll.cmake() do exe
   run(`$exe
       -DJulia_EXECUTABLE=$julia_exec
       -DJlCxx_DIR=$jlcxx_cmake_dir
-      -DCMAKE_BUILD_TYPE=Release
+      -DCMAKE_BUILD_TYPE=$(cxx_coverage ? "Debug" : "Release")
+      -DNORMALIZ_JULIA_ENABLE_COVERAGE=$(cxx_coverage ? "ON" : "OFF")
       -Dnormaliz_prefix=$(jll_artifact_dir(normaliz_jll))
       -Dgmp_prefix=$(jll_artifact_dir(normaliz_jll.GMP_jll))
       -Dmpfr_prefix=$(jll_artifact_dir(normaliz_jll.MPFR_jll))
@@ -67,7 +71,7 @@ CMake_jll.cmake() do exe
 
   run(`$exe
       --build $(builddir)
-      --config Release
+      --config $(cxx_coverage ? "Debug" : "Release")
       --
       -j$(div(Sys.CPU_THREADS,2))
   `)
diff --git a/deps/src/CMakeLists.txt b/deps/src/CMakeLists.txt
index 95af051..60b7071 100644
--- a/deps/src/CMakeLists.txt
+++ b/deps/src/CMakeLists.txt
@@ -18,6 +18,9 @@ set(CMAKE_CXX_STANDARD 14)
 
 set(CMAKE_INSTALL_RPATH "${CMAKE_INSTALL_PREFIX}/lib;${JlCxx_location}")
 
+option(NORMALIZ_JULIA_ENABLE_COVERAGE
+       "Build libnormaliz_julia with C++ coverage instrumentation" OFF)
+
 include_directories(
     ${gmp_prefix}/include
     ${normaliz_prefix}/include
@@ -28,6 +31,17 @@ include_directories(
 
 add_library(${JL_TARGET} SHARED normaliz.cpp)
 
+if(NORMALIZ_JULIA_ENABLE_COVERAGE)
+    if(CMAKE_CXX_COMPILER_ID MATCHES "GNU|Clang")
+        message(STATUS "Building ${JL_TARGET} with C++ coverage flags")
+        target_compile_options(${JL_TARGET} PRIVATE --coverage -O0 -g)
+        target_link_libraries(${JL_TARGET} --coverage)
+    else()
+        message(FATAL_ERROR
+                "C++ coverage is only supported with GCC or Clang")
+    endif()
+endif()
+
 target_link_libraries(${JL_TARGET}
     JlCxx::cxxwrap_julia
     JlCxx::cxxwrap_julia_stl
diff --git a/test/runtests.jl b/test/runtests.jl
index 39e2031..1bf0c81 100644
--- a/test/runtests.jl
+++ b/test/runtests.jl
@@ -238,6 +238,21 @@ end
   @test occursin("Complex", err.value.msg)
 end
 
+@testset "cone property output types" begin
+  @test String(Normaliz._cone_property_output_type("HilbertBasis")) == "Matrix"
+  @test String(Normaliz._cone_property_output_type("ExtremeRaysFloat")) == "MatrixFloat"
+  @test String(Normaliz._cone_property_output_type("Grading")) == "Vector"
+  @test String(Normaliz._cone_property_output_type("TriangulationDetSum")) == "Integer"
+  @test String(Normaliz._cone_property_output_type("ExternalIndex")) == "GMPInteger"
+  @test String(Normaliz._cone_property_output_type("Multiplicity")) == "Rational"
+  @test String(Normaliz._cone_property_output_type("RenfVolume")) == "FieldElem"
+  @test String(Normaliz._cone_property_output_type("EuclideanVolume")) == "Float"
+  @test String(Normaliz._cone_property_output_type("EmbeddingDim")) == "MachineInteger"
+  @test String(Normaliz._cone_property_output_type("IsPointed")) == "Bool"
+  @test String(Normaliz._cone_property_output_type("Triangulation")) == "Complex"
+  @test String(Normaliz._cone_property_output_type("DefaultMode")) == "Void"
+end
+
 # TODO: reactivate these tests once Renf support is back
 #@testset "basic renf test" begin
 #  r = Normaliz.RenfClass("a4-5a2+5", "a", "1.9021+/-0.01")