diff --git a/Jenkinsfile b/Jenkinsfile
index 40ac2ccb7ab..1106a805fb7 100644
--- a/Jenkinsfile
+++ b/Jenkinsfile
@@ -287,8 +287,7 @@ pipeline {
                             unstash 'MathSetup'
                             if (!(params.optimizeUnitTests || isBranch('develop') || isBranch('master'))) {
                                 sh "echo O=1 >> make/local"
-                            }
-                            sh'''
+                            }                             sh'''
                                 CXX=${CLANG_CXX} CC=${CLANG_CC} cmake -S . -B \"build\" -DCMAKE_BUILD_TYPE=RELEASE -DSTAN_OPENCL=ON -DSTAN_OPENCL_PLATFORM_ID=${OPENCL_PLATFORM_ID_GPU} -DSTAN_OPENCL_DEVICE_ID=${OPENCL_DEVICE_ID_GPU} && \
                                 cd build && make -j${PARALLEL} test_unit_math_opencl_tests && ctest --output-on-failure --label-regex unit_math_opencl
                             '''
diff --git a/test/CMakeLists.txt b/test/CMakeLists.txt
index a777d9860fa..54806240344 100644
--- a/test/CMakeLists.txt
+++ b/test/CMakeLists.txt
@@ -98,7 +98,7 @@ function(add_gtest_grouped_test test_directory folder_test_name target_pch)
           string(REPLACE ".cpp" "" SUB_TEST_TARGET_NAME ${TMP_TEST_TARGET_NAME})
           list(APPEND ALL_SUB_TEST_TARGETS ${SUB_TEST_TARGET_NAME})
           add_executable(${SUB_TEST_TARGET_NAME} ${cpp_file})
-          target_compile_options(${SUB_TEST_TARGET_NAME} PUBLIC -Wno-misleading-indentation)
+          target_compile_options(${SUB_TEST_TARGET_NAME} PUBLIC -O1 -Wno-misleading-indentation)
           target_include_directories(${SUB_TEST_TARGET_NAME} PRIVATE ${CMAKE_SOURCE_DIR})
           target_precompile_headers(${SUB_TEST_TARGET_NAME} REUSE_FROM ${target_pch})
           target_link_libraries(${SUB_TEST_TARGET_NAME}
diff --git a/test/unit/CMakeLists.txt b/test/unit/CMakeLists.txt
index ec86fc13eb9..28c5a77402f 100644
--- a/test/unit/CMakeLists.txt
+++ b/test/unit/CMakeLists.txt
@@ -14,6 +14,14 @@ target_precompile_headers(unit_pch PRIVATE
     "$<$<COMPILE_LANGUAGE:CXX>:<gtest/gtest.h$<ANGLE-R>>"
     "$<$<COMPILE_LANGUAGE:C>:<stddef.h$<ANGLE-R>>"
     )
+target_compile_options(unit_pch PUBLIC -O1 -Wno-misleading-indentation)
+if (STAN_OPENCL)
+target_link_libraries(unit_pch OpenCL::OpenCL)
+target_include_directories(unit_pch PRIVATE ${CLCPP_SOURCE_DIR}/include)
+endif()
+if (STAN_MPI)
+target_link_libraries(unit_pch Boost::mpi MPI::MPI_CXX)
+endif()
 
 target_link_libraries(unit_pch
   gtest_main benchmark::benchmark TBB::tbb