diff --git a/lib/jkqtcommon/jkqtpbasicimagetools.cpp b/lib/jkqtcommon/jkqtpbasicimagetools.cpp
index 67b3b038e5..f19cc1c7ef 100644
--- a/lib/jkqtcommon/jkqtpbasicimagetools.cpp
+++ b/lib/jkqtcommon/jkqtpbasicimagetools.cpp
@@ -38,7 +38,7 @@ const int JKQTPImageTools::LUTSIZE = 256;
 
 QMap<int, JKQTPImageTools::LUTData > JKQTPImageTools::global_jkqtpimagetools_lutstore = JKQTPImageTools::getDefaultLUTs();
 int JKQTPImageTools::global_next_userpalette = JKQTPMathImageFIRST_REGISTERED_USER_PALETTE;
-std::mutex JKQTPImageTools::lutMutex = std::mutex();
+std::mutex JKQTPImageTools::lutMutex;
 
 
 
diff --git a/lib/jkqtplotter/jkqtpbaseplotter.cpp b/lib/jkqtplotter/jkqtpbaseplotter.cpp
index c0402e40a0..90bb387907 100644
--- a/lib/jkqtplotter/jkqtpbaseplotter.cpp
+++ b/lib/jkqtplotter/jkqtpbaseplotter.cpp
@@ -55,7 +55,7 @@
 
 QString JKQTBasePlotter::globalUserSettigsFilename="";
 QString JKQTBasePlotter::globalUserSettigsPrefix="";
-std::mutex JKQTBasePlotter::globalUserSettingsMutex = std::mutex();
+std::mutex JKQTBasePlotter::globalUserSettingsMutex;
 JKQTPSynchronized<QList<JKQTPPaintDeviceAdapter*>> JKQTBasePlotter::jkqtpPaintDeviceAdapters;
 JKQTPSynchronized<QList<JKQTPSaveDataAdapter*>> JKQTBasePlotter::jkqtpSaveDataAdapters;