diff --git a/CMakeLists.txt b/CMakeLists.txt
index fe4551c9..727cb2ae 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -485,7 +485,7 @@ if(OCOS_ENABLE_BLINGFIRE)
 endif()
 
 if(OCOS_ENABLE_GPT2_TOKENIZER OR OCOS_ENABLE_WORDPIECE_TOKENIZER)
-  target_include_directories(ocos_operators PRIVATE ${json_SOURCE_DIR}/single_include)
+  target_include_directories(ocos_operators PRIVATE ${nlohmann_json_SOURCE_DIR}/single_include)
   list(APPEND ocos_libraries nlohmann_json::nlohmann_json)
 endif()
 
diff --git a/cmake/externals/json.cmake b/cmake/externals/json.cmake
index 32f08567..9e9f179b 100644
--- a/cmake/externals/json.cmake
+++ b/cmake/externals/json.cmake
@@ -1,11 +1,11 @@
-FetchContent_Declare(json
+FetchContent_Declare(nlohmann_json
   GIT_REPOSITORY https://github.com/nlohmann/json.git
   GIT_TAG v3.10.5)
 
 set(JSON_BuildTests OFF CACHE INTERNAL "")
 
-FetchContent_GetProperties(json)
-if(NOT json_POPULATED)
-  FetchContent_Populate(json)
-  add_subdirectory(${json_SOURCE_DIR} ${json_BINARY_DIR} EXCLUDE_FROM_ALL)
+FetchContent_GetProperties(nlohmann_json)
+if(NOT nlohmann_json_POPULATED)
+  FetchContent_Populate(nlohmann_json)
+  add_subdirectory(${nlohmann_json_SOURCE_DIR} ${nlohmann_json_BINARY_DIR} EXCLUDE_FROM_ALL)
 endif()