diff --git a/src/plugins/projectexplorer/abstractmsvctoolchain.cpp b/src/plugins/projectexplorer/abstractmsvctoolchain.cpp
index afc9304adbb..922918081e8 100644
--- a/src/plugins/projectexplorer/abstractmsvctoolchain.cpp
+++ b/src/plugins/projectexplorer/abstractmsvctoolchain.cpp
@@ -107,7 +107,7 @@ ToolChain::CompilerFlags AbstractMsvcToolChain::compilerFlags(const QStringList
  */
 WarningFlags AbstractMsvcToolChain::warningFlags(const QStringList &cflags) const
 {
-    WarningFlags flags;
+    WarningFlags flags = WarningFlags::NoWarnings;
     foreach (QString flag, cflags) {
         if (!flag.isEmpty() && flag[0] == QLatin1Char('-'))
             flag[0] = QLatin1Char('/');