diff --git a/CMakeLists.txt b/CMakeLists.txt
index 6d06be4..a2cddd9 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -29,13 +29,20 @@ target_include_directories(${PROJECT_NAME} PUBLIC "include")
 # Link required libraries
 # --------------------------------------------------------------------------------------------------------
 
-include(FetchContent)
+find_path(EXPECTED_INCLUDE_DIRS "tl/expected.hpp")
 
-FetchContent_Declare(expected GIT_REPOSITORY "https://github.com/TartanLlama/expected")
-
-option(EXPECTED_BUILD_TESTS "" OFF)
-option(EXPECTED_BUILD_PACKAGE "" OFF)
-FetchContent_MakeAvailable(expected)
+if(EXPECTED_INCLUDE_DIRS)
+  message(STATUS "Using system-installed tl::expected")
+  add_library(tl_expected INTERFACE)
+  target_include_directories(tl_expected INTERFACE ${EXPECTED_INCLUDE_DIRS})
+  add_library(tl::expected ALIAS tl_expected)
+else()
+  message(STATUS "Fetching tl::expected from GitHub")
+  include(FetchContent)
+  FetchContent_Declare(expected GIT_REPOSITORY "https://github.com/TartanLlama/expected")
+  option(EXPECTED_BUILD_TESTS "" OFF)
+  option(EXPECTED_BUILD_PACKAGE "" OFF)
+  FetchContent_MakeAvailable(expected)
 
 target_link_libraries(${PROJECT_NAME} PUBLIC tl::expected)