diff --git a/CMakeLists.txt b/CMakeLists.txt
index 16016d0..ad2f2f9 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -6,12 +6,14 @@ project(aocpp
     LANGUAGES C CXX
 )
 
-include(CheckIPOSupported)
-check_ipo_supported(RESULT result OUTPUT output)
-if(result)
-  set(CMAKE_INTERPROCEDURAL_OPTIMIZATION TRUE)
-else()
-  message(WARNING "IPO is not supported: ${output}")
+if(NOT CMAKE_BUILD_TYPE MATCHES "^Debug$")
+  include(CheckIPOSupported)
+  check_ipo_supported(RESULT result OUTPUT output)
+  if(result)
+    set(CMAKE_INTERPROCEDURAL_OPTIMIZATION TRUE)
+  else()
+    message(WARNING "IPO is not supported: ${output}")
+  endif()
 endif()
 
 find_package(PkgConfig)