diff --git a/cmake/QtBuildInternalsExtra.cmake.in b/cmake/QtBuildInternalsExtra.cmake.in
index ffc9d90f8..0b3a7d59e 100644
--- a/cmake/QtBuildInternalsExtra.cmake.in
+++ b/cmake/QtBuildInternalsExtra.cmake.in
@@ -51,8 +51,8 @@ endif()
 set(QT_WILL_INSTALL @QT_WILL_INSTALL@ CACHE BOOL
     "Boolean indicating if doing a Qt prefix build (vs non-prefix build)." FORCE)
 
-set(QT_SOURCE_TREE "@QT_SOURCE_TREE@" CACHE PATH
-"A path to the source tree of the previously configured QtBase project." FORCE)
+# set(QT_SOURCE_TREE "@QT_SOURCE_TREE@" CACHE PATH
+# "A path to the source tree of the previously configured QtBase project." FORCE)
 
 # Propagate decision of building tests and examples to other repositories.
 set(QT_BUILD_TESTS @QT_BUILD_TESTS@ CACHE BOOL "Build the testing tree.")