diff --git a/CMakeLists.txt b/CMakeLists.txt
index 5454df2b..28529e73 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -24,9 +24,11 @@ cmake_minimum_required(VERSION 3.9 FATAL_ERROR)
 
 # Detect if Check is being used in another build as a subproject
 # probably with command FetchContent*().
-set(THIS_IS_MAIN_PROJECT TRUE)
+set(THIS_IS_SUBPROJECT FALSE)
 if(DEFINED PROJECT_NAME)
-    set(THIS_IS_MAIN_PROJECT FALSE)
+  set(THIS_IS_SUBPROJECT TRUE)
+  message(STATUS "Turned off installing because Check is a subproject.")
+  message(STATUS "Turned off building tests because Check is a subproject.")
 endif()
 
 if(POLICY CMP0090)
@@ -400,62 +402,65 @@ set(CONFIG_HEADER ${CMAKE_CURRENT_BINARY_DIR}/config.h)
 #
 configure_file(${CMAKE_CURRENT_SOURCE_DIR}/cmake/check_stdint.h.in
   ${CMAKE_CURRENT_BINARY_DIR}/check_stdint.h @ONLY)
-install(
-  FILES ${CMAKE_CURRENT_BINARY_DIR}/check_stdint.h
-  DESTINATION ${CMAKE_INSTALL_INCLUDEDIR}
-)
+if(NOT THIS_IS_SUBPROJECT)
+  install(
+    FILES ${CMAKE_CURRENT_BINARY_DIR}/check_stdint.h
+    DESTINATION ${CMAKE_INSTALL_INCLUDEDIR})
+endif()
 
 ###############################################################################
 # Generate "check.pc", the package config (pkgconfig) file for libtool
-set(prefix_save "${PREFIX}")
-set(prefix "${CMAKE_INSTALL_PREFIX}")
-set(exec_prefix "\${prefix}")
-set(libdir "\${exec_prefix}/lib")
-set(includedir "\${prefix}/include")
-set(VERSION "${PROJECT_VERSION}")
-
-if (HAVE_SUBUNIT)
-  set(LIBSUBUNIT_PC "libsubunit")
-else (HAVE_SUBINIT)
-  set(LIBSUBUNIT_PC "")
-endif (HAVE_SUBUNIT)
-
-if (CHECK_ENABLE_GCOV)
-  set(GCOV_LIBS "-lgcov")
-else (CHECK_ENABLE_GCOV)
-  set(GCOV_LIBS "")
-endif (CHECK_ENABLE_GCOV)
-
-set(PTHREAD_LIBS "")
-set(LIBS "")
-
-if (HAVE_LIBM)
-  set(LIBS "${LIBS} -lm")
-endif (HAVE_LIBM)
-
-if (HAVE_LIBRT)
-  set(LIBS "${LIBS} -lrt")
-endif (HAVE_LIBRT)
-
-set(PTHREAD_CFLAGS "-pthread")
-
-configure_file(check.pc.in check.pc @ONLY)
-
-unset(PTHREAD_CFLAGS)
-unset(LIBS)
-unset(PTHREAD_LIBS)
-unset(GCOV_LIBS)
-unset(LIBSUBUNIT_PC)
-unset(VERSION)
-unset(includedir)
-unset(libdir)
-unset(exec_prefix)
-set(PREFIX "${prefix_save}")
-
-install(
-  FILES ${CMAKE_CURRENT_BINARY_DIR}/check.pc
-  DESTINATION ${CMAKE_INSTALL_LIBDIR}/pkgconfig
-)
+if(NOT THIS_IS_SUBPROJECT)
+  set(prefix_save "${PREFIX}")
+  set(prefix "${CMAKE_INSTALL_PREFIX}")
+  set(exec_prefix "\${prefix}")
+  set(libdir "\${exec_prefix}/lib")
+  set(includedir "\${prefix}/include")
+  set(VERSION "${PROJECT_VERSION}")
+
+  if (HAVE_SUBUNIT)
+    set(LIBSUBUNIT_PC "libsubunit")
+  else (HAVE_SUBINIT)
+    set(LIBSUBUNIT_PC "")
+  endif (HAVE_SUBUNIT)
+
+  if (CHECK_ENABLE_GCOV)
+    set(GCOV_LIBS "-lgcov")
+  else (CHECK_ENABLE_GCOV)
+    set(GCOV_LIBS "")
+  endif (CHECK_ENABLE_GCOV)
+
+  set(PTHREAD_LIBS "")
+  set(LIBS "")
+
+  if (HAVE_LIBM)
+    set(LIBS "${LIBS} -lm")
+  endif (HAVE_LIBM)
+
+  if (HAVE_LIBRT)
+    set(LIBS "${LIBS} -lrt")
+  endif (HAVE_LIBRT)
+
+  set(PTHREAD_CFLAGS "-pthread")
+
+  configure_file(check.pc.in check.pc @ONLY)
+
+  unset(PTHREAD_CFLAGS)
+  unset(LIBS)
+  unset(PTHREAD_LIBS)
+  unset(GCOV_LIBS)
+  unset(LIBSUBUNIT_PC)
+  unset(VERSION)
+  unset(includedir)
+  unset(libdir)
+  unset(exec_prefix)
+  set(PREFIX "${prefix_save}")
+
+  install(
+    FILES ${CMAKE_CURRENT_BINARY_DIR}/check.pc
+    DESTINATION ${CMAKE_INSTALL_LIBDIR}/pkgconfig
+  )
+endif()
 
 ###############################################################################
 # Subdirectories
@@ -465,7 +470,7 @@ add_subdirectory(checkmk)
 
 ###############################################################################
 # Unit tests
-if (BUILD_TESTING AND THIS_IS_MAIN_PROJECT)
+if(BUILD_TESTING AND NOT THIS_IS_SUBPROJECT)
   add_subdirectory(tests)
   add_test(NAME check_check COMMAND check_check)
   add_test(NAME check_check_export COMMAND check_check_export)
@@ -494,39 +499,41 @@ if (BUILD_TESTING AND THIS_IS_MAIN_PROJECT)
       WORKING_DIRECTORY ${CMAKE_CURRENT_BINARY_DIR}/tests
       COMMAND sh ${CMAKE_CURRENT_SOURCE_DIR}/tests/test_set_max_msg_size.sh)
   endif(UNIX OR MINGW OR MSYS)
-endif (BUILD_TESTING AND THIS_IS_MAIN_PROJECT)
+endif()
 
 ###############################################################################
 # Export project, prepare a config and config-version files
-string(TOLOWER ${PROJECT_NAME} EXPORT_NAME)
-include(CMakePackageConfigHelpers)
-configure_package_config_file(
-  ${CMAKE_CURRENT_SOURCE_DIR}/cmake/${EXPORT_NAME}-config.cmake.in
-  ${CMAKE_CURRENT_BINARY_DIR}/cmake/${EXPORT_NAME}-config.cmake
-  INSTALL_DESTINATION ${CMAKE_INSTALL_LIBDIR}/${EXPORT_NAME}/cmake
-)
-write_basic_package_version_file(
-  ${CMAKE_CURRENT_BINARY_DIR}/cmake/${EXPORT_NAME}-config-version.cmake
-  VERSION ${PROJECT_VERSION}
-  COMPATIBILITY AnyNewerVersion
-)
-
-export(EXPORT check-targets
-  FILE "${CMAKE_CURRENT_BINARY_DIR}/cmake/${EXPORT_NAME}-targets.cmake"
-  NAMESPACE "${PROJECT_NAME}::"
-)
-
-install(EXPORT check-targets
-  NAMESPACE "${PROJECT_NAME}::"
-  FILE "${EXPORT_NAME}-targets.cmake"
-  DESTINATION ${CMAKE_INSTALL_LIBDIR}/cmake/${EXPORT_NAME}
-)
-install(
-  FILES
-    "${CMAKE_CURRENT_BINARY_DIR}/cmake/${EXPORT_NAME}-config.cmake"
-    "${CMAKE_CURRENT_BINARY_DIR}/cmake/${EXPORT_NAME}-config-version.cmake"
-  DESTINATION ${CMAKE_INSTALL_LIBDIR}/cmake/${EXPORT_NAME}
-)
+if(NOT THIS_IS_SUBPROJECT)
+  string(TOLOWER ${PROJECT_NAME} EXPORT_NAME)
+  include(CMakePackageConfigHelpers)
+  configure_package_config_file(
+    ${CMAKE_CURRENT_SOURCE_DIR}/cmake/${EXPORT_NAME}-config.cmake.in
+    ${CMAKE_CURRENT_BINARY_DIR}/cmake/${EXPORT_NAME}-config.cmake
+    INSTALL_DESTINATION ${CMAKE_INSTALL_LIBDIR}/${EXPORT_NAME}/cmake
+  )
+  write_basic_package_version_file(
+    ${CMAKE_CURRENT_BINARY_DIR}/cmake/${EXPORT_NAME}-config-version.cmake
+    VERSION ${PROJECT_VERSION}
+    COMPATIBILITY AnyNewerVersion
+  )
+
+  export(EXPORT check-targets
+    FILE "${CMAKE_CURRENT_BINARY_DIR}/cmake/${EXPORT_NAME}-targets.cmake"
+    NAMESPACE "${PROJECT_NAME}::"
+  )
+
+  install(EXPORT check-targets
+    NAMESPACE "${PROJECT_NAME}::"
+    FILE "${EXPORT_NAME}-targets.cmake"
+    DESTINATION ${CMAKE_INSTALL_LIBDIR}/cmake/${EXPORT_NAME}
+  )
+  install(
+    FILES
+      "${CMAKE_CURRENT_BINARY_DIR}/cmake/${EXPORT_NAME}-config.cmake"
+      "${CMAKE_CURRENT_BINARY_DIR}/cmake/${EXPORT_NAME}-config-version.cmake"
+    DESTINATION ${CMAKE_INSTALL_LIBDIR}/cmake/${EXPORT_NAME}
+  )
+endif()
 
 # Store the current build directory in the CMake user package registry.
 # This helps dependent projects use a package from the current
@@ -540,7 +547,9 @@ install(
 # this side effect should not be enabled by default.
 # Therefore CMake 3.15 and above prefer that export(PACKAGE) does nothing
 # unless an explicit CMAKE_EXPORT_PACKAGE_REGISTRY variable is set.
-export(PACKAGE "${PROJECT_NAME}")
+if(NOT THIS_IS_SUBPROJECT)
+  export(PACKAGE "${PROJECT_NAME}")
+endif()
 
 # vim: shiftwidth=2:softtabstop=2:tabstop=2:expandtab:autoindent
 
diff --git a/checkmk/CMakeLists.txt b/checkmk/CMakeLists.txt
index 325b8944..cd201308 100644
--- a/checkmk/CMakeLists.txt
+++ b/checkmk/CMakeLists.txt
@@ -27,7 +27,7 @@ configure_file(checkmk.in checkmk @ONLY)
 file(COPY doc/checkmk.1 DESTINATION man/man1)
 
 option(INSTALL_CHECKMK "Install checkmk" ON)
-if(INSTALL_CHECKMK)
+if(INSTALL_CHECKMK AND NOT THIS_IS_SUBPROJECT)
   install(
     FILES ${CMAKE_CURRENT_BINARY_DIR}/checkmk
     DESTINATION ${CMAKE_INSTALL_BINDIR}
@@ -37,7 +37,7 @@ if(INSTALL_CHECKMK)
     DIRECTORY ${CMAKE_CURRENT_BINARY_DIR}/man
     DESTINATION ${CMAKE_INSTALL_DATAROOTDIR}
   )
-endif(INSTALL_CHECKMK)
+endif()
 
 # vim: shiftwidth=2:softtabstop=2:tabstop=2:expandtab:autoindent
 
diff --git a/src/CMakeLists.txt b/src/CMakeLists.txt
index 1e75ee5e..24d5c11c 100644
--- a/src/CMakeLists.txt
+++ b/src/CMakeLists.txt
@@ -182,13 +182,15 @@ target_include_directories(checkShared
     $<INSTALL_INTERFACE:include>
 )
 
-install(TARGETS check checkShared
-  EXPORT check-targets
-  ARCHIVE DESTINATION ${CMAKE_INSTALL_LIBDIR}
-  LIBRARY DESTINATION ${CMAKE_INSTALL_LIBDIR}
-  RUNTIME DESTINATION ${CMAKE_INSTALL_BINDIR}
-  PUBLIC_HEADER DESTINATION ${CMAKE_INSTALL_INCLUDEDIR}
-)
+if(NOT THIS_IS_SUBPROJECT)
+  install(TARGETS check checkShared
+    EXPORT check-targets
+    ARCHIVE DESTINATION ${CMAKE_INSTALL_LIBDIR}
+    LIBRARY DESTINATION ${CMAKE_INSTALL_LIBDIR}
+    RUNTIME DESTINATION ${CMAKE_INSTALL_BINDIR}
+    PUBLIC_HEADER DESTINATION ${CMAKE_INSTALL_INCLUDEDIR}
+  )
+endif()
 
 # vim: shiftwidth=2:softtabstop=2:tabstop=2:expandtab:autoindent