diff --git a/include/CMakeLists.txt b/include/CMakeLists.txt
index 67c66c8..4621271 100644
--- a/include/CMakeLists.txt
+++ b/include/CMakeLists.txt
@@ -18,4 +18,5 @@
 # Make config.h available in an out-of-source build. ssl-opt.sh requires it.
 if (NOT ${CMAKE_CURRENT_BINARY_DIR} STREQUAL ${CMAKE_CURRENT_SOURCE_DIR})
     link_to_source(mbedtls)
+    link_to_source(psa)
 endif()