diff --git a/CMakeLists.txt b/CMakeLists.txt
index 06329c0699..6ca9377612 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -1,11 +1,19 @@
 # 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()
 
 project(openrct2 CXX)
 
+include(CheckIPOSupported)
+check_ipo_supported(RESULT IPO_SUPPORTED OUTPUT IPO_LOG)
+if(IPO_SUPPORTED)
+    message(INFO "IPO supported")
+else()
+    message(WARNING "IPO not supported: ${IPO_LOG}")
+endif()
+
 if (NOT MSVC)
     include(FindPkgConfig)
 endif ()
@@ -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)
@@ -227,6 +165,94 @@ if (WITH_TESTS)
     include("${ROOT_DIR}/test/tests/CMakeLists.txt" NO_POLICY_SCOPE)
 endif ()
 
+# Check if a flag exists and add it to the compiler (so, not the linker) options
+function (ADD_CHECK_CXX_COMPILER_FLAG _CXXFLAGS _CACHE_VAR _FLAG)
+    CHECK_CXX_COMPILER_FLAG("${_FLAG}" "${_CACHE_VAR}")
+    if (${_CACHE_VAR})
+        if(TARGET ${PROJECT})
+            target_compile_options(${PROJECT} PRIVATE ${_FLAG})
+        endif()
+        if(TARGET ${PROJECT}-cli)
+            target_compile_options(${PROJECT}-cli PRIVATE ${_FLAG})
+        endif()
+    else ()
+        message(STATUS "Unsupported CXXFLAG: ${_FLAG}")
+    endif ()
+endfunction ()
+
+# Check if a flag exists and add it to the compiler and the linker options
+function (ADD_CHECK_CXX_FLAG _CXXFLAGS _CACHE_VAR _FLAG)
+    CHECK_CXX_COMPILER_FLAG("${_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 "${CMAKE_CXX_FLAGS} -Wno-error=objc-method-access")
+    endif()
+
+    # On mingw all code is already PIC, this will avoid compiler error on redefining this option
+    if (NOT MINGW)
+        set(CMAKE_POSITION_INDEPENDENT_CODE ON)
+    endif ()
+
+    if (APPLE AND NOT USE_MMAP)
+        set(CMAKE_POSITION_INDEPENDENT_CODE OFF)
+    else ()
+        set(CMAKE_POSITION_INDEPENDENT_CODE ON)
+    endif ()
+endif ()
+
+
 # Install
 # Don't recurse, grab all *.txt and *.md files
 file(GLOB DOC_FILES "${ROOT_DIR}/distribution/*.txt")
diff --git a/src/openrct2-cli/CMakeLists.txt b/src/openrct2-cli/CMakeLists.txt
index 0f6e093162..441324fa44 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 ${CMAKE_SOURCE_DIR}/CMakeCache.txt")
 endif ()
@@ -15,6 +15,10 @@ set (PROJECT openrct2-cli)
 project(${PROJECT} CXX)
 add_executable(${PROJECT} ${OPENRCT2_CLI_SOURCES})
 
+if(IPO_SUPPORTED)
+    set_property(TARGET ${PROJECT} PROPERTY INTERPROCEDURAL_OPTIMIZATION TRUE)
+endif()
+
 target_link_libraries(${PROJECT} "libopenrct2")
 
 # Needed for interactive console
diff --git a/src/openrct2-ui/CMakeLists.txt b/src/openrct2-ui/CMakeLists.txt
index 40e120d4aa..031b46f8c8 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 ${CMAKE_SOURCE_DIR}/CMakeCache.txt")
 endif ()
@@ -50,6 +50,10 @@ set (PROJECT openrct2)
 project(${PROJECT} CXX)
 add_executable(${PROJECT} ${OPENRCT2_UI_SOURCES} ${OPENRCT2_UI_MM_SOURCES})
 
+if(IPO_SUPPORTED)
+    set_property(TARGET ${PROJECT} PROPERTY INTERPROCEDURAL_OPTIMIZATION TRUE)
+endif()
+
 target_link_libraries(${PROJECT} "libopenrct2"
                                  ${SDL2_LDFLAGS}
                                  ${SPEEX_LDFLAGS})
diff --git a/src/openrct2/CMakeLists.txt b/src/openrct2/CMakeLists.txt
index bc54c296c1..0471db4717 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 ()