diff --git a/cmake/QtSetup.cmake b/cmake/QtSetup.cmake
index bdb93e6fd00..ede764b5428 100644
--- a/cmake/QtSetup.cmake
+++ b/cmake/QtSetup.cmake
@@ -77,7 +77,7 @@ if (PROJECT_NAME STREQUAL "QtBase" AND NOT QT_BUILD_STANDALONE_TESTS)
     if(CMAKE_CROSSCOMPILING)
         set(__qt_prefix "${CMAKE_STAGING_PREFIX}")
     else()
-        set(__qt_prefix_ "")
+        set(__qt_prefix "")
     endif()
     if(__qt_prefix STREQUAL "")
         set(__qt_prefix "${CMAKE_INSTALL_PREFIX}")