diff --git a/CMakeLists.txt b/CMakeLists.txt
index 2146a029..47022cdc 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -102,9 +102,9 @@ if(CMAKE_C_COMPILER_ID MATCHES "AppleClang|Clang|GNU")
   endif()
 endif()
 
-if(NOT(CMAKE_BUILD_TYPE MATCHES "Release|release|RelWithDebInfo|relwithdebinfo"))
-  string(TOLOWER "${CMAKE_BUILD_TYPE}" build_type)
-  set(mi_basename "mimalloc-${build_type}")
+string(TOLOWER "${CMAKE_BUILD_TYPE}" LOWERCASE_CMAKE_BUILD_TYPE)
+if(NOT(LOWERCASE_CMAKE_BUILD_TYPE MATCHES "^(release|relwithdebinfo|minsizerel)$"))
+  set(mi_basename "mimalloc-${LOWERCASE_CMAKE_BUILD_TYPE}")
 else()
   if(MI_SECURE MATCHES "ON")
     set(mi_basename "mimalloc-secure")