diff --git a/src/cpp/CMakeLists.txt b/src/cpp/CMakeLists.txt
index b1a91eb..ff44703 100644
--- a/src/cpp/CMakeLists.txt
+++ b/src/cpp/CMakeLists.txt
@@ -580,7 +580,7 @@ endif()
 
 # external libraries
 add_subdirectory(ext)
-include_directories(SYSTEM "${FMT_SOURCE_DIR}/include")
+find_package(fmt REQUIRED)
 
 # shared library
 add_subdirectory(shared_core)
diff --git a/src/cpp/ext/CMakeLists.txt b/src/cpp/ext/CMakeLists.txt
index 2e08e79..0b4d5fa 100644
--- a/src/cpp/ext/CMakeLists.txt
+++ b/src/cpp/ext/CMakeLists.txt
@@ -14,6 +14,3 @@
 #
 
 project (EXT)
-
-add_subdirectory(fmt)
-