diff --git a/bitcoin-qt.pro b/bitcoin-qt.pro
index 64468d324..ac0904a73 100644
--- a/bitcoin-qt.pro
+++ b/bitcoin-qt.pro
@@ -101,14 +101,15 @@ contains(BITCOIN_NEED_QT_PLUGINS, 1) {
 INCLUDEPATH += src/leveldb/include src/leveldb/helpers
 LIBS += $$PWD/src/leveldb/libleveldb.a $$PWD/src/leveldb/libmemenv.a
 !win32 {
-    genleveldb.commands = cd $$PWD/src/leveldb && CC=$$QMAKE_CC CXX=$$QMAKE_CXX $(MAKE) OPT=\"$$QMAKE_CXXFLAGS\" libleveldb.a libmemenv.a
+    # we use QMAKE_CXXFLAGS_RELEASE even without RELEASE=1 because we use RELEASE to indicate linking preferences not -O preferences
+    genleveldb.commands = cd $$PWD/src/leveldb && CC=$$QMAKE_CC CXX=$$QMAKE_CXX $(MAKE) OPT=\"$$QMAKE_CXXFLAGS $$QMAKE_CXXFLAGS_RELEASE\" libleveldb.a libmemenv.a
 } else {
     # make an educated guess about what the ranlib command is called
     isEmpty(QMAKE_RANLIB) {
         QMAKE_RANLIB = $$replace(QMAKE_STRIP, strip, ranlib)
     }
     LIBS += -lshlwapi
-    genleveldb.commands = cd $$PWD/src/leveldb && CC=$$QMAKE_CC CXX=$$QMAKE_CXX TARGET_OS=OS_WINDOWS_CROSSCOMPILE $(MAKE) OPT=\"$$QMAKE_CXXFLAGS\" libleveldb.a libmemenv.a && $$QMAKE_RANLIB $$PWD/src/leveldb/libleveldb.a && $$QMAKE_RANLIB $$PWD/src/leveldb/libmemenv.a
+    genleveldb.commands = cd $$PWD/src/leveldb && CC=$$QMAKE_CC CXX=$$QMAKE_CXX TARGET_OS=OS_WINDOWS_CROSSCOMPILE $(MAKE) OPT=\"$$QMAKE_CXXFLAGS $$QMAKE_CXXFLAGS_RELEASE\" libleveldb.a libmemenv.a && $$QMAKE_RANLIB $$PWD/src/leveldb/libleveldb.a && $$QMAKE_RANLIB $$PWD/src/leveldb/libmemenv.a
 }
 genleveldb.target = $$PWD/src/leveldb/libleveldb.a
 genleveldb.depends = FORCE