diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index 78688bf..5250a33 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -7,11 +7,14 @@ on:
 
 jobs:
   build-and-test:
+    name: build-and-test (${{ matrix.cxx }}${{ matrix.asan && ', asan' || '' }})
     runs-on: ubuntu-24.04
     strategy:
       fail-fast: false
       matrix:
         cxx: [g++-14, clang++-19]
+        # The sanitizer executables build in their own job, in parallel with the plain one.
+        asan: [false, true]
 
     steps:
     - uses: actions/checkout@v4
@@ -34,14 +37,15 @@ jobs:
           -DCMAKE_BUILD_TYPE=Release \
           -DCMAKE_CXX_COMPILER=${{ matrix.cxx }} \
           -DNUMSIM_MATERIALS_BUILD_TESTS=ON \
-          -DNUMSIM_MATERIALS_BUILD_REPORTS=ON \
-          -DNUMSIM_MATERIALS_REPORT_TESTS=ON \
+          -DNUMSIM_SANITIZER_TESTS=${{ matrix.asan && 'ON' || 'OFF' }} \
+          -DNUMSIM_MATERIALS_BUILD_REPORTS=${{ matrix.asan && 'OFF' || 'ON' }} \
+          -DNUMSIM_MATERIALS_REPORT_TESTS=${{ matrix.asan && 'OFF' || 'ON' }} \
           -DNUMSIM_MATERIALS_BUILD_EXAMPLES=OFF \
           -DNUMSIM_MATERIALS_ENABLE_PLOTTING=OFF \
           -DNUMSIM_MATERIALS_DEBUG_CHECKS=ON
 
     - name: Build
-      run: cmake --build build -j$(nproc)
+      run: cmake --build build -j$(nproc) ${{ matrix.asan && '--target numsim_materials_asan_tests' || '' }}
 
     - name: Test
-      run: cd build && ctest --output-on-failure
+      run: cd build && ctest --output-on-failure -j$(nproc) ${{ matrix.asan && '-R _asan$' || '' }}
diff --git a/tests/CMakeLists.txt b/tests/CMakeLists.txt
index 1844164..4bb570b 100644
--- a/tests/CMakeLists.txt
+++ b/tests/CMakeLists.txt
@@ -1,8 +1,28 @@
 find_package(Threads REQUIRED)
 
+option(NUMSIM_MATERIALS_BATCH_TESTS "Compile single-file tests several to a translation unit" ON)
+set(NUMSIM_MATERIALS_TEST_BATCH_SIZE 6 CACHE STRING "Test files per batch")
+# Tests that need their own flags or check what a lone translation unit includes.
+set(_numsim_standalone_tests test_material_conformance test_host_neutral_includes)
+set(_numsim_batched_sources)
+set(_numsim_test_targets)
+
 macro(add_numsim_test TARGET_NAME)
-  numsim_add_test(${TARGET_NAME} SOURCES ${ARGN}
-    LINK numsim-materials::numsim-materials Threads::Threads)
+  set(_srcs ${ARGN})
+  list(LENGTH _srcs _nsrcs)
+  set(_c_symbols)
+  if(_nsrcs EQUAL 1)
+    # C entry points ignore the batch namespaces and would be defined twice.
+    file(STRINGS "${_srcs}" _c_symbols REGEX "NUMSIM_MATERIALS_DEFINE_|extern \"C\"")
+  endif()
+  if(NUMSIM_MATERIALS_BATCH_TESTS AND _nsrcs EQUAL 1 AND NOT _c_symbols
+     AND NOT "${TARGET_NAME}" IN_LIST _numsim_standalone_tests)
+    list(APPEND _numsim_batched_sources "${CMAKE_CURRENT_SOURCE_DIR}/${_srcs}")
+  else()
+    numsim_add_test(${TARGET_NAME} SOURCES ${ARGN}
+      LINK numsim-materials::numsim-materials Threads::Threads)
+    list(APPEND _numsim_test_targets ${TARGET_NAME})
+  endif()
 endmacro()
 
 add_numsim_test(test_property_graph test_property_graph.cpp)
@@ -89,6 +109,39 @@ add_numsim_test(test_voigt_composite test_voigt_composite.cpp)
 add_numsim_test(test_hencky_elasticity test_hencky_elasticity.cpp)
 add_numsim_test(test_material_point test_material_point.cpp)
 
+# One executable per batch: shared templates are instantiated and compiled once per batch, not once per file.
+list(LENGTH _numsim_batched_sources _nbatched)
+set(_first 0)
+set(_batch 0)
+while(_first LESS _nbatched)
+  list(SUBLIST _numsim_batched_sources ${_first} ${NUMSIM_MATERIALS_TEST_BATCH_SIZE} _srcs)
+  string(REPLACE ";" "|" _arg "${_srcs}")
+  set(_name test_batch_${_batch})
+  set(_out "${CMAKE_CURRENT_BINARY_DIR}/${_name}.cpp")
+  add_custom_command(OUTPUT "${_out}"
+    COMMAND ${CMAKE_COMMAND} "-DOUT=${_out}" "-DSOURCES=${_arg}" -P "${CMAKE_CURRENT_SOURCE_DIR}/batch_tests.cmake"
+    DEPENDS ${_srcs} "${CMAKE_CURRENT_SOURCE_DIR}/batch_tests.cmake" VERBATIM)
+  add_custom_target(${_name}_source DEPENDS "${_out}")
+  numsim_add_test(${_name} SOURCES "${_out}" INCLUDE_DIRS "${CMAKE_CURRENT_SOURCE_DIR}"
+    LINK numsim-materials::numsim-materials Threads::Threads)
+  list(APPEND _numsim_test_targets ${_name})
+  foreach(_t ${_name} ${_name}_asan ${_name}_tsan)
+    if(TARGET ${_t})
+      add_dependencies(${_t} ${_name}_source)
+    endif()
+  endforeach()
+  math(EXPR _first "${_first} + ${NUMSIM_MATERIALS_TEST_BATCH_SIZE}")
+  math(EXPR _batch "${_batch} + 1")
+endwhile()
+
+# Builds only the sanitizer executables (the CI sanitizer job).
+add_custom_target(numsim_materials_asan_tests)
+foreach(_t IN LISTS _numsim_test_targets)
+  if(TARGET ${_t}_asan)
+    add_dependencies(numsim_materials_asan_tests ${_t}_asan)
+  endif()
+endforeach()
+
 # Data dumper for plotting (not a test — standalone executable)
 add_executable(plot_data plot_data.cpp)
 target_link_libraries(plot_data PRIVATE numsim-materials::numsim-materials)
diff --git a/tests/batch_tests.cmake b/tests/batch_tests.cmake
new file mode 100644
index 0000000..3c7eac5
--- /dev/null
+++ b/tests/batch_tests.cmake
@@ -0,0 +1,23 @@
+# cmake -DOUT=<file> -DSOURCES=<a|b|...> -P batch_tests.cmake
+# Writes one translation unit holding several test files, each in its own namespace.
+# Every #include of the files is hoisted above the namespaces, so the inner ones are no-ops.
+string(REPLACE "|" ";" SOURCES "${SOURCES}")
+set(_includes)
+set(_bodies)
+set(_k 0)
+foreach(_src IN LISTS SOURCES)
+  file(STRINGS "${_src}" _lines REGEX "^[ \t]*#[ \t]*include")
+  list(APPEND _includes ${_lines})
+  string(APPEND _bodies "namespace numsim_test_batch_${_k} {\n#include \"${_src}\"\n}\n")
+  math(EXPR _k "${_k} + 1")
+endforeach()
+list(REMOVE_DUPLICATES _includes)
+list(JOIN _includes "\n" _includes)
+set(_content "// Generated by tests/batch_tests.cmake.\n${_includes}\n\n${_bodies}")
+if(EXISTS "${OUT}")
+  file(READ "${OUT}" _old)
+  if(_old STREQUAL _content)
+    return()
+  endif()
+endif()
+file(WRITE "${OUT}" "${_content}")