diff --git a/CMakeLists.txt b/CMakeLists.txt
index 71c3a1a6..7ca224fa 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -55,7 +55,7 @@ set(gtest_force_shared_crt ON CACHE BOOL "" FORCE)
 FetchContent_MakeAvailable(googletest)
 include(GoogleTest)
 
-add_subdirectory(au)
+add_subdirectory(include)
 
 # Configure how Au will be installed.
 #
diff --git a/au/CMakeLists.txt b/au/CMakeLists.txt
index 7b237dc0..35492412 100644
--- a/au/CMakeLists.txt
+++ b/au/CMakeLists.txt
@@ -12,7 +12,7 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
-include(../cmake/HeaderOnlyLibrary.cmake)
+include("${PROJECT_SOURCE_DIR}/cmake/HeaderOnlyLibrary.cmake")
 
 #
 # Publicly exported targets
diff --git a/cmake/HeaderOnlyLibrary.cmake b/cmake/HeaderOnlyLibrary.cmake
index f30ac651..971e19fa 100644
--- a/cmake/HeaderOnlyLibrary.cmake
+++ b/cmake/HeaderOnlyLibrary.cmake
@@ -45,7 +45,7 @@ function(header_only_library)
     ${ARG_NAME}
     INTERFACE
     FILE_SET HEADERS
-    BASE_DIRS ${CMAKE_SOURCE_DIR}
+    BASE_DIRS "${PROJECT_SOURCE_DIR}/include"
     FILES ${ARG_HEADERS}
   )
   if (DEFINED ARG_DEPS)
@@ -71,6 +71,7 @@ function(header_only_library)
     TARGETS ${ARG_NAME}
     EXPORT ${AU_EXPORT_SET_NAME}
     FILE_SET HEADERS
+    INCLUDES DESTINATION "${CMAKE_INSTALL_INCLUDEDIR}"
   )
 
   # Add the test, if requested.
diff --git a/include/CMakeLists.txt b/include/CMakeLists.txt
new file mode 100644
index 00000000..3ca0e0dc
--- /dev/null
+++ b/include/CMakeLists.txt
@@ -0,0 +1 @@
+add_subdirectory(au)
diff --git a/include/au b/include/au
new file mode 120000
index 00000000..9b388e88
--- /dev/null
+++ b/include/au
@@ -0,0 +1 @@
+../au/
\ No newline at end of file