diff --git a/CMakeLists.txt b/CMakeLists.txt
index 933e367..de79677 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -91,8 +91,13 @@ if (${IS_GNU} OR ${IS_CLANG})
     endif()
 endif()
 
-include(CheckIPOSupported)
-check_ipo_supported(RESULT CMAKE_INTERPROCEDURAL_OPTIMIZATION_RELEASE LANGUAGES CXX)
+if (NOT DEFINED CMAKE_INTERPROCEDURAL_OPTIMIZATION_RELEASE)
+    set(USER_DEFINED_INTERPROCEDURAL_OPTIMIZATION_RELEASE NO)
+    include(CheckIPOSupported)
+    check_ipo_supported(RESULT CMAKE_INTERPROCEDURAL_OPTIMIZATION_RELEASE LANGUAGES CXX)
+else()
+    set(USER_DEFINED_INTERPROCEDURAL_OPTIMIZATION_RELEASE YES)
+endif()
 
 if (${IS_GNU})
     if (CMAKE_CXX_COMPILER_VERSION VERSION_LESS ${MINIMAL_GNU} AND NOT ${IGNORE_MINIMAL_COMPILER_VERSION})
@@ -109,7 +114,7 @@ elseif(${IS_CLANG})
     if (CMAKE_CXX_COMPILER_VERSION VERSION_LESS ${MINIMAL_CLANG} AND NOT ${IGNORE_MINIMAL_COMPILER_VERSION})
         message(FATAL_ERROR "Clang ${MINIMAL_CLANG} or higher is required.")
     endif()
-    if (${CMAKE_INTERPROCEDURAL_OPTIMIZATION_RELEASE} OR MINGW) # CMAKE_INTERPROCEDURAL_OPTIMIZATION_RELEASE is false on llvm-mingw toolchains even though it is supported
+    if (${CMAKE_INTERPROCEDURAL_OPTIMIZATION_RELEASE} OR (MINGW AND NOT USER_DEFINED_INTERPROCEDURAL_OPTIMIZATION_RELEASE)) # CMAKE_INTERPROCEDURAL_OPTIMIZATION_RELEASE is false on llvm-mingw toolchains even though it is supported
         set(CMAKE_CXX_FLAGS_RELEASE "${CMAKE_CXX_FLAGS_RELEASE} -flto=thin")
         if (NOT DEFINED EMSCRIPTEN)
             set(CMAKE_CXX_FLAGS_RELEASE "${CMAKE_CXX_FLAGS_RELEASE} -fwhole-program-vtables")