diff --git a/README.md b/README.md
index 7a95463..313c8fd 100644
--- a/README.md
+++ b/README.md
@@ -54,7 +54,7 @@ cmake --build .
 ```
 
 For building against preinstalled system libraries of the used vendor
-libraries (system maintainers), additionally define
+libraries (e.g. for use by system maintainers), additionally define
 `BLISP_USE_SYSTEM_LIBRARIES`, e.g. using following commands:
 ```bash
 mkdir build && cd build
diff --git a/tools/blisp/CMakeLists.txt b/tools/blisp/CMakeLists.txt
index e694d7f..ac16d1d 100644
--- a/tools/blisp/CMakeLists.txt
+++ b/tools/blisp/CMakeLists.txt
@@ -2,17 +2,19 @@ set(ARGTABLE3_ENABLE_TESTS OFF CACHE BOOL "Enable unit tests")
 set(ARGTABLE3_ENABLE_EXAMPLES OFF CACHE BOOL "Enable examples")
 #set(ARGTABLE3_REPLACE_GETOPT OFF CACHE BOOL "Replace getopt in the system C library")
 
-if(BLISP_USE_SYSTEM_LIBRARIES)
-    find_package(Argtable3)
-else()
-    add_subdirectory(${CMAKE_SOURCE_DIR}/vendor/argtable3 ${CMAKE_CURRENT_BINARY_DIR}/argtable3)
-endif()
-
 add_executable(blisp src/main.c src/cmd/write.c src/util.c src/common.c src/cmd/iot.c)
 
-target_include_directories(blisp PRIVATE
-        "${CMAKE_SOURCE_DIR}/include"
+if(BLISP_USE_SYSTEM_LIBRARIES)
+    find_package(Argtable3 REQUIRED)
+else()
+    add_subdirectory(${CMAKE_SOURCE_DIR}/vendor/argtable3 ${CMAKE_CURRENT_BINARY_DIR}/argtable3)
+
+    target_include_directories(blisp PRIVATE
         "${CMAKE_SOURCE_DIR}/vendor/argtable3/src")
+endif()
+
+target_include_directories(blisp PRIVATE
+        "${CMAKE_SOURCE_DIR}/include")
 
 target_link_libraries(blisp PRIVATE
         argtable3