diff --git a/build_system/seqan3-install.cmake b/build_system/seqan3-install.cmake
index 8dcdc617d2..0f2d37f6cd 100644
--- a/build_system/seqan3-install.cmake
+++ b/build_system/seqan3-install.cmake
@@ -24,5 +24,7 @@ install (FILES "${SEQAN3_CLONE_DIR}/build_system/seqan3-config.cmake"
 # install seqan3 header files in /include/seqan3
 install (DIRECTORY "${SEQAN3_INCLUDE_DIR}/seqan3" TYPE INCLUDE)
 
-install (DIRECTORY "${sdsl-lite_SOURCE_DIR}/include/sdsl" DESTINATION "${CMAKE_INSTALL_INCLUDEDIR}/seqan3/vendor/sdsl")
-install (DIRECTORY "${cereal_SOURCE_DIR}/include/cereal" DESTINATION "${CMAKE_INSTALL_INCLUDEDIR}/seqan3/vendor/cereal")
+install (DIRECTORY "${SEQAN3_SDSL_INCLUDE_DIR}/include/sdsl"
+         DESTINATION "${CMAKE_INSTALL_INCLUDEDIR}/seqan3/vendor/sdsl")
+install (DIRECTORY "${SEQAN3_CEREAL_INCLUDE_DIR}/include/cereal"
+         DESTINATION "${CMAKE_INSTALL_INCLUDEDIR}/seqan3/vendor/cereal")
diff --git a/test/seqan3-test.cmake b/test/seqan3-test.cmake
index f5e7624d4a..813382b19f 100644
--- a/test/seqan3-test.cmake
+++ b/test/seqan3-test.cmake
@@ -95,11 +95,11 @@ if (NOT TARGET seqan3::test)
         if (CMAKE_CXX_COMPILER_VERSION VERSION_GREATER_EQUAL 12)
             target_compile_options (seqan3_test INTERFACE "-Wno-interference-size")
         endif ()
-    endif ()
 
-    # Warn about failed return value optimization.
-    if (CMAKE_CXX_COMPILER_VERSION VERSION_GREATER_EQUAL 14)
-        target_compile_options (seqan3_test INTERFACE "-Wnrvo")
+        # Warn about failed return value optimization.
+        if (CMAKE_CXX_COMPILER_VERSION VERSION_GREATER_EQUAL 14)
+            target_compile_options (seqan3_test INTERFACE "-Wnrvo")
+        endif ()
     endif ()
 
     # GCC on arm64 (M1): Disable notes about ABI changes. Example: