diff --git a/CMakeLists.txt b/CMakeLists.txt
index 21f67c0..014544d 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -7,6 +7,11 @@ set(CMAKE_CXX_STANDARD 17)
 set (CMAKE_EXPORT_COMPILE_COMMANDS ON)
 
 project (shared)
+
+if (CMAKE_CURRENT_SOURCE_DIR STREQUAL CMAKE_SOURCE_DIR)
+  set (LIBSHARED_IS_TOP_LEVEL ON)
+endif ()
+
 include (CXXSniffer)
 
 include (CheckFunctionExists)
diff --git a/src/CMakeLists.txt b/src/CMakeLists.txt
index 4e17455..4c39464 100644
--- a/src/CMakeLists.txt
+++ b/src/CMakeLists.txt
@@ -56,9 +56,11 @@ set (shared_SRCS Args.cpp
 
 add_library (shared STATIC ${shared_SRCS})
 
-set (CMAKE_INSTALL_LIBDIR lib CACHE PATH "Output directory for libraries")
-install (TARGETS shared DESTINATION lib)
-install (FILES ${shared_HEADERS} DESTINATION include)
+if (LIBSHARED_IS_TOP_LEVEL)
+  set (CMAKE_INSTALL_LIBDIR lib CACHE PATH "Output directory for libraries")
+  install (TARGETS shared DESTINATION lib)
+  install (FILES ${shared_HEADERS} DESTINATION include)
+endif ()
 
 add_executable (lex_executable lex.cpp)
 target_link_libraries (lex_executable shared)