diff --git a/Framework/Algorithms/src/FindPeakBackground.cpp b/Framework/Algorithms/src/FindPeakBackground.cpp
index 04408b05d9d0c5ba46cfb45b2dac572c52aebedc..047bb0748a29536e74291b11089fd189ca149331 100644
--- a/Framework/Algorithms/src/FindPeakBackground.cpp
+++ b/Framework/Algorithms/src/FindPeakBackground.cpp
@@ -157,9 +157,9 @@ void FindPeakBackground::exec() {
     Statistics stats = getStatistics(maskedY);
     Ymean = stats.mean;
     Yvariance = stats.standard_deviation * stats.standard_deviation;
-    Ysigma = std::sqrt(
-        (moment4(maskedY, xn, Ymean) - (xn - 3.0) / (xn - 1.0) * Yvariance) /
-        xn);
+    Ysigma = std::sqrt((moment4(maskedY, static_cast<size_t>(xn), Ymean) -
+                        (xn - 3.0) / (xn - 1.0) * Yvariance) /
+                       xn);
     MantidVec::const_iterator it =
         std::max_element(maskedY.begin(), maskedY.end());
     const size_t pos = it - maskedY.begin();
diff --git a/Framework/MDAlgorithms/src/ConvertCWSDExpToMomentum.cpp b/Framework/MDAlgorithms/src/ConvertCWSDExpToMomentum.cpp
index 9ac61977a6685a0c964f956f7c6619ac2c176078..3e208518d505c6369b81f1ea1c58679d50659b03 100644
--- a/Framework/MDAlgorithms/src/ConvertCWSDExpToMomentum.cpp
+++ b/Framework/MDAlgorithms/src/ConvertCWSDExpToMomentum.cpp
@@ -203,11 +203,12 @@ void ConvertCWSDExpToMomentum::addMDEvents(bool usevirtual) {
   std::string sep("");
   if (m_dataDir.size() > 0) {
     // Determine system
-    const bool isWindows(false);
 #if _WIN64
-    isWindows = true;
-#elif _WIND32
-    isWindows = true;
+    const bool isWindows = true;
+#elif _WIN32
+    const bool isWindows = true;
+#else
+    const bool isWindows = false;
 #endif
     if (isWindows && *m_dataDir.rbegin() != '\\') {
       sep = "\\";