diff --git a/package/qt5/qt5base/qmake.conf.in b/package/qt5/qt5base/qmake.conf.in
index f14527aa7f..26bee2cb39 100644
--- a/package/qt5/qt5base/qmake.conf.in
+++ b/package/qt5/qt5base/qmake.conf.in
@@ -15,7 +15,6 @@ QMAKE_CXX               = $${CROSS_COMPILE}g++
 # modifications to gcc-base.conf
 QMAKE_CFLAGS           += $${BR_COMPILER_CFLAGS}
 QMAKE_CXXFLAGS         += $${BR_COMPILER_CXXFLAGS}
-QMAKE_CXXFLAGS_RELEASE += -O3
 CONFIG                 += nostrip
 
 QMAKE_LIBS             += -lrt -lpthread -ldl