diff --git a/CMakeLists.txt b/CMakeLists.txt
index 895e2f71687..631f20e4e74 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -153,7 +153,7 @@ endif()
 option(LLVM_ENABLE_PEDANTIC "Compile with pedantic enabled." ON)
 option(LLVM_ENABLE_WERROR "Fail and stop if a warning is triggered." OFF)
 
-if( uppercase_CMAKE_BUILD_TYPE STREQUAL "RELEASE" )
+if( NOT uppercase_CMAKE_BUILD_TYPE STREQUAL "DEBUG" )
   option(LLVM_ENABLE_ASSERTIONS "Enable assertions" OFF)
 else()
   option(LLVM_ENABLE_ASSERTIONS "Enable assertions" ON)
diff --git a/cmake/modules/HandleLLVMOptions.cmake b/cmake/modules/HandleLLVMOptions.cmake
index 2939fa2afa2..bc6dd0ccd8f 100644
--- a/cmake/modules/HandleLLVMOptions.cmake
+++ b/cmake/modules/HandleLLVMOptions.cmake
@@ -17,9 +17,9 @@ if( LLVM_ENABLE_ASSERTIONS )
   if( NOT MSVC )
     add_definitions( -D_DEBUG )
   endif()
-  # On Release builds cmake automatically defines NDEBUG, so we
+  # On non-Debug builds cmake automatically defines NDEBUG, so we
   # explicitly undefine it:
-  if( uppercase_CMAKE_BUILD_TYPE STREQUAL "RELEASE" )
+  if( NOT uppercase_CMAKE_BUILD_TYPE STREQUAL "DEBUG" )
     add_definitions( -UNDEBUG )
     # Also remove /D NDEBUG to avoid MSVC warnings about conflicting defines.
     string (REGEX REPLACE "(^| )[/-]D *NDEBUG($| )" " "