diff --git a/CMakeLists.txt b/CMakeLists.txt
index aa347ae66..19c56a413 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -24,6 +24,7 @@ if (NOT (EXISTS "${CMAKE_SOURCE_DIR}/src/CMakeLists.txt"))
           "``python contrib/cmake/bootstrap.py create``")
 endif()
 
+set(CMAKE_USER_MAKE_RULES_OVERRIDE_CXX "${CMAKE_CURRENT_SOURCE_DIR}/cmake/cxx_compiler_flags_overrides.cmake")
 project(Z3 CXX)
 
 ################################################################################
diff --git a/contrib/cmake/cmake/cxx_compiler_flags_overrides.cmake b/contrib/cmake/cmake/cxx_compiler_flags_overrides.cmake
new file mode 100644
index 000000000..59966f424
--- /dev/null
+++ b/contrib/cmake/cmake/cxx_compiler_flags_overrides.cmake
@@ -0,0 +1,14 @@
+# This file overrides the default compiler flags for CMake's built-in
+# configurations (CMAKE_BUILD_TYPE). Most compiler flags should not be set here.
+# The main purpose is to have very fine grained control of the compiler flags.
+
+# We only override the defaults for Clang and GCC right now.
+# CMake's MSVC logic is complicated so for now it's better to just inherit CMake's defaults.
+if (("${CMAKE_CXX_COMPILER_ID}" MATCHES "Clang") OR ("${CMAKE_CXX_COMPILER_ID}" MATCHES "GNU"))
+  # Taken from Modules/Compiler/GNU.cmake
+  set(CMAKE_CXX_FLAGS_INIT "")
+  set(CMAKE_CXX_FLAGS_DEBUG_INIT "-g -O0")
+  set(CMAKE_CXX_FLAGS_MINSIZEREL_INIT "-Os -DNDEBUG")
+  set(CMAKE_CXX_FLAGS_RELEASE_INIT "-O3 -DNDEBUG")
+  set(CMAKE_CXX_FLAGS_RELWITHDEBINFO_INIT "-O2 -g -DNDEBUG")
+endif()