diff --git a/CMakeLists.txt b/CMakeLists.txt
index 06329c0699..6338c54611 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -1,5 +1,5 @@
 # CMAKE project for openrct2
-cmake_minimum_required(VERSION 3.8)
+cmake_minimum_required(VERSION 3.9)
 if (CMAKE_BINARY_DIR STREQUAL CMAKE_SOURCE_DIR)
     message(FATAL_ERROR "Building in-source is not supported! Create a build dir and remove ${CMAKE_SOURCE_DIR}/CMakeCache.txt")
 endif()
@@ -52,6 +52,14 @@ if (PORTABLE OR WIN32)
     set(CMAKE_INSTALL_RPATH "$ORIGIN")
 endif ()
 
+# LIST of supported flags, use SET_CHECK_CXX_FLAGS() to apply to target.
+# Use ADD_CHECK_CXX_COMPILER_FLAG() to add to list.
+list(APPEND SUPPORTED_CHECK_CXX_COMPILER_FLAGS)
+
+include(cmake/ipo.cmake)
+list(APPEND IPO_ENABLED_BUILDS RELEASE RELWITHDEBINFO MINSIZEREL)
+ipo_enable("${IPO_ENABLED_BUILDS}")
+
 # Describe current version in terms of closest tag
 execute_process(
     COMMAND git describe HEAD
@@ -80,76 +88,6 @@ execute_process(
     ERROR_QUIET
 )
 
-function (ADD_CHECK_CXX_COMPILER_FLAG _CXXFLAGS _CACHE_VAR _FLAG)
-    CHECK_CXX_COMPILER_FLAG("${_FLAG}" "${_CACHE_VAR}")
-    if (${_CACHE_VAR})
-        set(${_CXXFLAGS} "${${_CXXFLAGS}} ${_FLAG}" PARENT_SCOPE)
-    else ()
-        message(STATUS "Unsupported CXXFLAG: ${_FLAG}")
-    endif ()
-endfunction ()
-
-if (MSVC)
-    set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} /utf-8 /permissive- /Zc:externConstexpr /WX")
-    set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} /wd4244") # C4244: 'conversion_type': conversion from 'type1' to 'type2', possible loss of data
-
-    add_definitions(-D_CRT_SECURE_NO_WARNINGS)
-    add_definitions(-D_SCL_SECURE_NO_WARNINGS)
-    add_definitions(-D__SSE4_1__)
-    add_definitions(-D__AVX2__)
-else ()
-    ADD_CHECK_CXX_COMPILER_FLAG(CMAKE_CXX_FLAGS CXX_WARN_NULL_DEREFERENCE -Wnull-dereference)
-    ADD_CHECK_CXX_COMPILER_FLAG(CMAKE_CXX_FLAGS CXX_WARN_SUGGEST_FINAL_TYPES -Wsuggest-final-types)
-    ADD_CHECK_CXX_COMPILER_FLAG(CMAKE_CXX_FLAGS CXX_WARN_SUGGEST_FINAL_METHODS -Wsuggest-final-methods)
-    ADD_CHECK_CXX_COMPILER_FLAG(CMAKE_CXX_FLAGS CXX_WARN_SUGGEST_OVERRIDE -Wsuggest-override)
-    ADD_CHECK_CXX_COMPILER_FLAG(CMAKE_CXX_FLAGS CXX_WARN_DUPLICATED_COND -Wduplicated-cond)
-    ADD_CHECK_CXX_COMPILER_FLAG(CMAKE_CXX_FLAGS CXX_WARN_NON_VIRTUAL_DTOR -Wnon-virtual-dtor)
-    ADD_CHECK_CXX_COMPILER_FLAG(CMAKE_CXX_FLAGS CXX_WARN_MISSING_VARIABLE_DECLARATIONS -Wmissing-variable-declarations)
-    ADD_CHECK_CXX_COMPILER_FLAG(CMAKE_CXX_FLAGS CXX_WARN_DUPLICATED_BRANCHES -Wduplicated-branches)
-    ADD_CHECK_CXX_COMPILER_FLAG(CMAKE_CXX_FLAGS CXX_WARN_RESTRICT -Wrestrict)
-    ADD_CHECK_CXX_COMPILER_FLAG(CMAKE_CXX_FLAGS CXX_WARN_MISSING_FIELD_INITIALIZERS -Wmissing-field-initializers)
-    ADD_CHECK_CXX_COMPILER_FLAG(CMAKE_CXX_FLAGS CXX_WARN_UNREACHABLE_CODE_BREAK -Wunreachable-code-break)
-    ADD_CHECK_CXX_COMPILER_FLAG(CMAKE_CXX_FLAGS CXX_WARN_LOGICAL_OP -Wlogical-op)
-    ADD_CHECK_CXX_COMPILER_FLAG(CMAKE_CXX_FLAGS CXX_WARN_RANGE_LOOP_ANALYSIS -Wrange-loop-analysis)
-    ADD_CHECK_CXX_COMPILER_FLAG(CMAKE_CXX_FLAGS CXX_WARN_TAUTOLOGICAL_ZERO_COMPARE -Wtautological-unsigned-zero-compare)
-    ADD_CHECK_CXX_COMPILER_FLAG(CMAKE_CXX_FLAGS CXX_WNO_CLOBBERED -Wno-clobbered)
-    # Disabled due to problems compiling OpenSSL on macOS.
-    # ADD_CHECK_CXX_COMPILER_FLAG(CMAKE_CXX_FLAGS CXX_WARN_DOCUMENTATION -Wdocumentation)
-
-    # Items below are not supported by ICC
-    if (NOT MINGW)
-        # Do not enable for MinGW, as its headers contain redundant declarations of builtin functions
-        ADD_CHECK_CXX_COMPILER_FLAG(CMAKE_CXX_FLAGS CXX_WARN_REDUNDANT_DECLS -Wredundant-decls)
-    endif ()
-    ADD_CHECK_CXX_COMPILER_FLAG(CMAKE_CXX_FLAGS CXX_WARN_IGNORED_QUALIFIERS -Wignored-qualifiers)
-
-    # -Wstrict-overflow is only active when -fstrict-overflow is enabled, but -fstrict-overflow
-    # is enabled on -O2, -O3, -Os. This should help catch bugs locally before they reach Travis
-    # As of 2a435bf -Wstrict-overflow=1 passes, but higher values do not.
-    set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -fstrict-overflow")
-    ADD_CHECK_CXX_COMPILER_FLAG(CMAKE_CXX_FLAGS CXX_WARN_STRICT_OVERFLOW -Wstrict-overflow=1)
-
-    # Compiler flags
-    set(DEBUG_LEVEL 0 CACHE STRING "Select debug level for compilation. Use value in range 0–3.")
-    set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -fstrict-aliasing -Werror -Wundef -Wmissing-declarations -Winit-self -Wall -Wextra -Wshadow")
-    set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -Wno-unknown-pragmas -Wno-missing-braces -Wno-comment -Wnonnull -Wno-unused-parameter")
-    set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -DDEBUG=${DEBUG_LEVEL}")
-
-    if(APPLE)
-        set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -Wno-error=objc-method-access")
-    endif()
-
-    # On mingw all code is already PIC, this will avoid compiler error on redefining this option
-    if (NOT MINGW)
-        set(CMAKE_POSITION_INDEPENDENT_CODE ON)
-    endif ()
-
-    if (APPLE AND NOT USE_MMAP)
-        set(CMAKE_POSITION_INDEPENDENT_CODE OFF)
-    else ()
-        set(CMAKE_POSITION_INDEPENDENT_CODE ON)
-    endif ()
-endif ()
 
 # Defines
 if (USE_MMAP)
@@ -203,6 +141,93 @@ elseif(CMAKE_SYSTEM_PROCESSOR MATCHES "i686.*|i386.*|x86.*|amd64.*|AMD64.*")
     set(X86 1)
 endif()
 
+# Check if a flag exists and add it to the list of compiler (so, not linker) options
+function (ADD_CHECK_CXX_COMPILER_FLAG _CXXFLAGS _CACHE_VAR _FLAG)
+    CHECK_CXX_COMPILER_FLAG("${_FLAG}" "${_CACHE_VAR}")
+    if (${_CACHE_VAR})
+        list(APPEND SUPPORTED_CHECK_CXX_COMPILER_FLAGS "${_FLAG}")
+    else ()
+        message(STATUS "Unsupported CXXFLAG: ${_FLAG}")
+    endif ()
+endfunction ()
+
+# Add check flags to a compile TARGET
+function (SET_CHECK_CXX_FLAGS _TARGET)
+    target_compile_options("${_TARGET}" PRIVATE "${SUPPORTED_CHECK_CXX_COMPILER_FLAGS}")
+endfunction()
+
+# Check if a flag exists and add it to the compiler and the linker options
+function (ADD_CHECK_CXX_FLAG _CXXFLAGS _CACHE_VAR _FLAG)
+    CHECK_CXX_COMPILER_FLAG("${_FLAG}" "${_CACHE_VAR}")
+    if (${_CACHE_VAR})
+        set(${_CXXFLAGS} "${${_CXXFLAGS}} ${_FLAG}" PARENT_SCOPE)
+    else ()
+        message(STATUS "Unsupported CXXFLAG: ${_FLAG}")
+    endif ()
+endfunction ()
+
+if (MSVC)
+    set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} /utf-8 /permissive- /Zc:externConstexpr /WX")
+    set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} /wd4244") # C4244: 'conversion_type': conversion from 'type1' to 'type2', possible loss of data
+
+    add_definitions(-D_CRT_SECURE_NO_WARNINGS)
+    add_definitions(-D_SCL_SECURE_NO_WARNINGS)
+    add_definitions(-D__SSE4_1__)
+    add_definitions(-D__AVX2__)
+else ()
+    ADD_CHECK_CXX_COMPILER_FLAG(CMAKE_CXX_FLAGS CXX_WARN_NULL_DEREFERENCE -Wnull-dereference)
+    ADD_CHECK_CXX_COMPILER_FLAG(CMAKE_CXX_FLAGS CXX_WARN_SUGGEST_FINAL_TYPES -Wsuggest-final-types)
+    ADD_CHECK_CXX_COMPILER_FLAG(CMAKE_CXX_FLAGS CXX_WARN_SUGGEST_FINAL_METHODS -Wsuggest-final-methods)
+    ADD_CHECK_CXX_COMPILER_FLAG(CMAKE_CXX_FLAGS CXX_WARN_SUGGEST_OVERRIDE -Wsuggest-override)
+    ADD_CHECK_CXX_COMPILER_FLAG(CMAKE_CXX_FLAGS CXX_WARN_DUPLICATED_COND -Wduplicated-cond)
+    ADD_CHECK_CXX_COMPILER_FLAG(CMAKE_CXX_FLAGS CXX_WARN_NON_VIRTUAL_DTOR -Wnon-virtual-dtor)
+    ADD_CHECK_CXX_COMPILER_FLAG(CMAKE_CXX_FLAGS CXX_WARN_MISSING_VARIABLE_DECLARATIONS -Wmissing-variable-declarations)
+    ADD_CHECK_CXX_COMPILER_FLAG(CMAKE_CXX_FLAGS CXX_WARN_DUPLICATED_BRANCHES -Wduplicated-branches)
+    ADD_CHECK_CXX_COMPILER_FLAG(CMAKE_CXX_FLAGS CXX_WARN_RESTRICT -Wrestrict)
+    ADD_CHECK_CXX_COMPILER_FLAG(CMAKE_CXX_FLAGS CXX_WARN_MISSING_FIELD_INITIALIZERS -Wmissing-field-initializers)
+    ADD_CHECK_CXX_COMPILER_FLAG(CMAKE_CXX_FLAGS CXX_WARN_UNREACHABLE_CODE_BREAK -Wunreachable-code-break)
+    ADD_CHECK_CXX_COMPILER_FLAG(CMAKE_CXX_FLAGS CXX_WARN_LOGICAL_OP -Wlogical-op)
+    ADD_CHECK_CXX_COMPILER_FLAG(CMAKE_CXX_FLAGS CXX_WARN_RANGE_LOOP_ANALYSIS -Wrange-loop-analysis)
+    ADD_CHECK_CXX_COMPILER_FLAG(CMAKE_CXX_FLAGS CXX_WARN_TAUTOLOGICAL_ZERO_COMPARE -Wtautological-unsigned-zero-compare)
+    ADD_CHECK_CXX_FLAG(CMAKE_CXX_FLAGS CXX_WNO_CLOBBERED -Wno-clobbered)
+    # Disabled due to problems compiling OpenSSL on macOS.
+    # ADD_CHECK_CXX_COMPILER_FLAG(CMAKE_CXX_FLAGS CXX_WARN_DOCUMENTATION -Wdocumentation)
+
+    # Items below are not supported by ICC
+    if (NOT MINGW)
+        # Do not enable for MinGW, as its headers contain redundant declarations of builtin functions
+        ADD_CHECK_CXX_COMPILER_FLAG(CMAKE_CXX_FLAGS CXX_WARN_REDUNDANT_DECLS -Wredundant-decls)
+    endif ()
+    ADD_CHECK_CXX_COMPILER_FLAG(CMAKE_CXX_FLAGS CXX_WARN_IGNORED_QUALIFIERS -Wignored-qualifiers)
+
+    # -Wstrict-overflow is only active when -fstrict-overflow is enabled, but -fstrict-overflow
+    # is enabled on -O2, -O3, -Os. This should help catch bugs locally before they reach Travis
+    # As of 2a435bf -Wstrict-overflow=1 passes, but higher values do not.
+    set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -fstrict-overflow")
+    ADD_CHECK_CXX_COMPILER_FLAG(CMAKE_CXX_FLAGS CXX_WARN_STRICT_OVERFLOW -Wstrict-overflow=1)
+
+    # Compiler flags
+    set(DEBUG_LEVEL 0 CACHE STRING "Select debug level for compilation. Use value in range 0–3.")
+    set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -fstrict-aliasing -Werror -Wundef -Wmissing-declarations -Winit-self -Wall -Wextra -Wshadow")
+    set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -Wno-unknown-pragmas -Wno-missing-braces -Wno-comment -Wnonnull -Wno-unused-parameter")
+    set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -DDEBUG=${DEBUG_LEVEL}")
+
+    if(APPLE)
+        set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -Wno-error=objc-method-access")
+    endif()
+
+    # On mingw all code is already PIC, this will avoid compiler error on redefining this option
+    if (NOT MINGW)
+        set(CMAKE_POSITION_INDEPENDENT_CODE ON)
+    endif ()
+
+    if (APPLE AND NOT USE_MMAP)
+        set(CMAKE_POSITION_INDEPENDENT_CODE OFF)
+    else ()
+        set(CMAKE_POSITION_INDEPENDENT_CODE ON)
+    endif ()
+endif ()
+
 # Include sub-projects
 include("${ROOT_DIR}/src/openrct2/CMakeLists.txt" NO_POLICY_SCOPE)
 include("${ROOT_DIR}/src/openrct2-cli/CMakeLists.txt" NO_POLICY_SCOPE)
diff --git a/cmake/ipo.cmake b/cmake/ipo.cmake
new file mode 100644
index 0000000000..7c77c62a20
--- /dev/null
+++ b/cmake/ipo.cmake
@@ -0,0 +1,34 @@
+# Helpers for inter-procedural optimizations (IPO)
+
+option(DISABLE_IPO "Disable IPO in supported release builds." OFF)
+
+# Enabled IPO for a LIST of CMake build types.
+# Provides IPO_BUILD_ENABLED to the parent scope.
+# Make sure to supply the build types in UPPER CASE
+function(ipo_enable IPO_ENABLED_BUILDS)
+    include(CheckIPOSupported)
+    check_ipo_supported(RESULT IPO_SUPPORTED OUTPUT IPO_LOG)
+
+    set(IPO_BUILD_ENABLED OFF PARENT_SCOPE)
+    string(TOUPPER "${CMAKE_BUILD_TYPE}" CMAKE_BUILD_TYPE_UPPER)
+    if(NOT CMAKE_BUILD_TYPE)
+        message(STATUS "CMAKE_BUILD_TYPE not explicitly set. Not enabling IPO.")
+    elseif(IPO_SUPPORTED AND ${CMAKE_BUILD_TYPE_UPPER} IN_LIST IPO_ENABLED_BUILDS)
+        if(NOT DISABLE_IPO)
+            message(STATUS "IPO supported and enabled in ${CMAKE_BUILD_TYPE}.")
+            set(IPO_BUILD_ENABLED ON PARENT_SCOPE)
+        else()
+            message(STATUS "IPO explicitly disabled.")
+        endif()
+    elseif(NOT IPO_SUPPORTED AND ${CMAKE_BUILD_TYPE_UPPER} IN_LIST IPO_ENABLED_BUILDS)
+        message(STATUS "IPO not supported: ${IPO_LOG}.")
+    endif()
+endfunction()
+
+# Sets appropriate IPO properties on target _target
+# if IPO is supported and enabled for the current build.
+function(ipo_set_target_properties _target)
+    if(IPO_BUILD_ENABLED)
+        set_property(TARGET ${_target} PROPERTY INTERPROCEDURAL_OPTIMIZATION TRUE)
+    endif()
+endfunction()
diff --git a/src/openrct2-cli/CMakeLists.txt b/src/openrct2-cli/CMakeLists.txt
index 0f6e093162..e2c444fdf9 100644
--- a/src/openrct2-cli/CMakeLists.txt
+++ b/src/openrct2-cli/CMakeLists.txt
@@ -1,5 +1,5 @@
 # CMAKE project for openrct2-cli (CLI-only build of OpenRCT2)
-cmake_minimum_required(VERSION 3.1)
+cmake_minimum_required(VERSION 3.9)
 if (CMAKE_BINARY_DIR STREQUAL CMAKE_SOURCE_DIR)
     message(FATAL_ERROR "Building in-source is not supported! Create a build dir and remove ${CMAKE_SOURCE_DIR}/CMakeCache.txt")
 endif ()
@@ -14,6 +14,7 @@ file(GLOB_RECURSE OPENRCT2_CLI_SOURCES
 set (PROJECT openrct2-cli)
 project(${PROJECT} CXX)
 add_executable(${PROJECT} ${OPENRCT2_CLI_SOURCES})
+ipo_set_target_properties(${PROJECT})
 
 target_link_libraries(${PROJECT} "libopenrct2")
 
diff --git a/src/openrct2-ui/CMakeLists.txt b/src/openrct2-ui/CMakeLists.txt
index 40e120d4aa..52bd7a62b9 100644
--- a/src/openrct2-ui/CMakeLists.txt
+++ b/src/openrct2-ui/CMakeLists.txt
@@ -1,5 +1,5 @@
 # CMAKE project for openrct2-ui (UI build of OpenRCT2)
-cmake_minimum_required(VERSION 3.1)
+cmake_minimum_required(VERSION 3.9)
 if (CMAKE_BINARY_DIR STREQUAL CMAKE_SOURCE_DIR)
     message(FATAL_ERROR "Building in-source is not supported! Create a build dir and remove ${CMAKE_SOURCE_DIR}/CMakeCache.txt")
 endif ()
@@ -49,6 +49,8 @@ endif ()
 set (PROJECT openrct2)
 project(${PROJECT} CXX)
 add_executable(${PROJECT} ${OPENRCT2_UI_SOURCES} ${OPENRCT2_UI_MM_SOURCES})
+SET_CHECK_CXX_FLAGS(${PROJECT})
+ipo_set_target_properties(${PROJECT})
 
 target_link_libraries(${PROJECT} "libopenrct2"
                                  ${SDL2_LDFLAGS}
diff --git a/src/openrct2/CMakeLists.txt b/src/openrct2/CMakeLists.txt
index 639e32925d..bccc763bd2 100644
--- a/src/openrct2/CMakeLists.txt
+++ b/src/openrct2/CMakeLists.txt
@@ -1,5 +1,5 @@
 # CMAKE project for libopenrct2 (core OpenRCT2 component)
-cmake_minimum_required(VERSION 3.7)
+cmake_minimum_required(VERSION 3.9)
 if (CMAKE_BINARY_DIR STREQUAL CMAKE_SOURCE_DIR)
     message(FATAL_ERROR "Building in-source is not supported! Create a build dir and remove ${CMAKE_SOURCE_DIR}/CMakeCache.txt")
 endif ()
@@ -74,6 +74,7 @@ set(PROJECT libopenrct2)
 project(${PROJECT} CXX)
 add_library(${PROJECT} ${OPENRCT2_CORE_SOURCES} ${OPENRCT2_CORE_MM_SOURCES} ${RCT2_SECTIONS})
 set_target_properties(${PROJECT} PROPERTIES PREFIX "")
+SET_CHECK_CXX_FLAGS(${PROJECT})
 
 if (benchmark_FOUND)
     message("Found Google benchmark, enabling support")
diff --git a/test/testpaint/CMakeLists.txt b/test/testpaint/CMakeLists.txt
index 83faee5fef..11c56ba2e1 100644
--- a/test/testpaint/CMakeLists.txt
+++ b/test/testpaint/CMakeLists.txt
@@ -83,6 +83,7 @@ file(GLOB_RECURSE ORCT2_TESTPAINT_SOURCES "${CMAKE_CURRENT_LIST_DIR}/*.c"
 set_source_files_properties(${CMAKE_CURRENT_LIST_DIR}/addresses.c PROPERTIES COMPILE_FLAGS -O0)
 
 add_executable(testpaint EXCLUDE_FROM_ALL ${ORCT2_RIDE_SOURCES} ${ORCT2_RIDE_DEP_SOURCES} ${ORCT2_TESTPAINT_SOURCES} ${RCT2_SECTIONS})
+SET_CHECK_CXX_FLAGS(testpaint)
 target_include_directories(testpaint PRIVATE "${ROOT_DIR}/src/")
 target_link_libraries(testpaint z)
 
diff --git a/test/tests/CMakeLists.txt b/test/tests/CMakeLists.txt
index 25d946547b..c8f2c923e0 100644
--- a/test/tests/CMakeLists.txt
+++ b/test/tests/CMakeLists.txt
@@ -137,6 +137,7 @@ set(INI_TEST_SOURCES
         "${ROOT_DIR}/src/openrct2/core/MemoryStream.cpp"
         )
 add_executable(test_ini ${INI_TEST_SOURCES})
+SET_CHECK_CXX_FLAGS(test_ini)
 target_link_libraries(test_ini ${GTEST_LIBRARIES} test-common ${LDL} z)
 add_test(NAME ini COMMAND test_ini)
 
@@ -145,12 +146,14 @@ set(STRING_TEST_SOURCES
         "${CMAKE_CURRENT_LIST_DIR}/StringTest.cpp"
         )
 add_executable(test_string ${STRING_TEST_SOURCES})
+SET_CHECK_CXX_FLAGS(test_string)
 target_link_libraries(test_string ${GTEST_LIBRARIES} test-common ${LDL} z)
 add_test(NAME string COMMAND test_string)
 
 # Localisation test
 set(STRING_TEST_SOURCES "${CMAKE_CURRENT_LIST_DIR}/Localisation.cpp")
 add_executable(test_localisation ${STRING_TEST_SOURCES})
+SET_CHECK_CXX_FLAGS(test_localisation)
 target_link_libraries(test_localisation ${GTEST_LIBRARIES} test-common ${LDL} z)
 add_test(NAME localisation COMMAND test_localisation)
 
@@ -158,6 +161,7 @@ if (NOT DISABLE_NETWORK)
     # Crypt tests
     add_executable(test_crypt "${CMAKE_CURRENT_LIST_DIR}/CryptTests.cpp"
                               "${CMAKE_CURRENT_LIST_DIR}/TestData.cpp")
+    SET_CHECK_CXX_FLAGS(test_crypt)
     target_link_libraries(test_crypt ${GTEST_LIBRARIES} libopenrct2)
     add_test(NAME Crypt COMMAND test_crypt)
 endif ()
@@ -165,6 +169,7 @@ endif ()
 # ImageImporter tests
 add_executable(test_imageimporter "${CMAKE_CURRENT_LIST_DIR}/ImageImporterTests.cpp"
                                   "${CMAKE_CURRENT_LIST_DIR}/TestData.cpp")
+SET_CHECK_CXX_FLAGS(test_imageimporter)
 target_link_libraries(test_imageimporter ${GTEST_LIBRARIES} libopenrct2)
 add_test(NAME ImageImporter COMMAND test_imageimporter)
 
@@ -172,6 +177,7 @@ add_test(NAME ImageImporter COMMAND test_imageimporter)
 set(RIDE_RATINGS_TEST_SOURCES "${CMAKE_CURRENT_LIST_DIR}/RideRatings.cpp"
                               "${CMAKE_CURRENT_LIST_DIR}/TestData.cpp")
 add_executable(test_ride_ratings ${RIDE_RATINGS_TEST_SOURCES})
+SET_CHECK_CXX_FLAGS(test_ride_ratings)
 target_link_libraries(test_ride_ratings ${GTEST_LIBRARIES} libopenrct2 ${LDL} z)
 add_test(NAME ride_ratings COMMAND test_ride_ratings)
 
@@ -179,6 +185,7 @@ add_test(NAME ride_ratings COMMAND test_ride_ratings)
 set(MULTILAUNCH_TEST_SOURCES "${CMAKE_CURRENT_LIST_DIR}/MultiLaunch.cpp"
                              "${CMAKE_CURRENT_LIST_DIR}/TestData.cpp")
 add_executable(test_multilaunch ${MULTILAUNCH_TEST_SOURCES})
+SET_CHECK_CXX_FLAGS(test_multilaunch)
 target_link_libraries(test_multilaunch ${GTEST_LIBRARIES} libopenrct2 ${LDL} z)
 add_test(NAME multilaunch COMMAND test_multilaunch)
 
@@ -186,6 +193,7 @@ add_test(NAME multilaunch COMMAND test_multilaunch)
 set(TILE_ELEMENT_TEST_SOURCES "${CMAKE_CURRENT_LIST_DIR}/TileElements.cpp"
                               "${CMAKE_CURRENT_LIST_DIR}/TestData.cpp")
 add_executable(test_tile_elements ${TILE_ELEMENT_TEST_SOURCES})
+SET_CHECK_CXX_FLAGS(test_tile_elements)
 target_link_libraries(test_tile_elements ${GTEST_LIBRARIES} libopenrct2 ${LDL} z)
 add_test(NAME tile_elements COMMAND test_tile_elements)
 
@@ -194,6 +202,7 @@ if (NOT DISABLE_NETWORK)
     set(REPLAY_TEST_SOURCES "${CMAKE_CURRENT_LIST_DIR}/ReplayTests.cpp"
                                   "${CMAKE_CURRENT_LIST_DIR}/TestData.cpp")
     add_executable(test_replays ${REPLAY_TEST_SOURCES})
+    SET_CHECK_CXX_FLAGS(test_replays)
     target_link_libraries(test_replays ${GTEST_LIBRARIES} libopenrct2 ${LDL} z)
     add_test(NAME replay_tests COMMAND test_replays)
 endif ()
@@ -202,5 +211,6 @@ endif ()
 set(PATHFINDING_TEST_SOURCES  "${CMAKE_CURRENT_LIST_DIR}/Pathfinding.cpp"
                               "${CMAKE_CURRENT_LIST_DIR}/TestData.cpp")
 add_executable(test_pathfinding ${PATHFINDING_TEST_SOURCES})
+SET_CHECK_CXX_FLAGS(test_pathfinding)
 target_link_libraries(test_pathfinding ${GTEST_LIBRARIES} libopenrct2 ${LDL} z)
 add_test(NAME pathfinding COMMAND test_pathfinding)