Index: dolfin/test/unit/cpp/CMakeLists.txt
===================================================================
--- dolfin.orig/test/unit/cpp/CMakeLists.txt
+++ dolfin/test/unit/cpp/CMakeLists.txt
@@ -31,6 +31,7 @@ set(TEST_SOURCES
 
 add_executable(unittests ${TEST_SOURCES})
 target_link_libraries(unittests PRIVATE Catch dolfin)
+target_include_directories(unittests PRIVATE ${DOLFIN_SOURCE_DIR} ${DOLFIN_SOURCE_DIR}/dolfin ${DOLFIN_BINARY_DIR})
 
 # Test target
 add_test(unittests unittests)
Index: dolfin/demo/CMakeLists.txt
===================================================================
--- dolfin.orig/demo/CMakeLists.txt
+++ dolfin/demo/CMakeLists.txt
@@ -6,6 +6,7 @@ cmake_minimum_required(VERSION 3.5)
 # Find DOLFIN config file (not used here, but check that the demo will
 # be able to find it
 #find_package(DOLFIN PATHS ${CMAKE_BINARY_DIR} REQUIRED)
+include_directories(${DOLFIN_SOURCE_DIR} ${DOLFIN_SOURCE_DIR}/dolfin ${DOLFIN_BINARY_DIR})
 
 # Documented demos
 add_subdirectory(documented/auto-adaptive-poisson/cpp)