diff --git a/MantidQt/MantidWidgets/inc/MantidQtMantidWidgets/MuonFitPropertyBrowser.h b/MantidQt/MantidWidgets/inc/MantidQtMantidWidgets/MuonFitPropertyBrowser.h
index c6b5b4db462838f95bebd849d2666a925a430722..8d3c44ed26500bcd0b05d0bd4a52b5237a9fbc3b 100644
--- a/MantidQt/MantidWidgets/inc/MantidQtMantidWidgets/MuonFitPropertyBrowser.h
+++ b/MantidQt/MantidWidgets/inc/MantidQtMantidWidgets/MuonFitPropertyBrowser.h
@@ -16,6 +16,7 @@ class QtEnumPropertyManager;
 class QtProperty;
 class QtBrowserItem;
 class QVBoxLayout;
+class QSplitter;
 
 namespace Mantid {
 namespace API {
@@ -112,6 +113,8 @@ private:
                                   const int nWorkspaces) const;
   /// Layout for extra widgets
   QVBoxLayout *m_additionalLayout;
+  /// Splitter for additional widgets
+  QSplitter *m_widgetSplitter;
   /// Names of workspaces to fit
   std::vector<std::string> m_workspacesToFit;
   /// Label to use for simultaneous fits
diff --git a/MantidQt/MantidWidgets/src/MuonFitPropertyBrowser.cpp b/MantidQt/MantidWidgets/src/MuonFitPropertyBrowser.cpp
index 854abf60186d4001f1b489450781273594d273ca..a5e49f86281f5d7b5f4b36196760fc22af6fba51 100644
--- a/MantidQt/MantidWidgets/src/MuonFitPropertyBrowser.cpp
+++ b/MantidQt/MantidWidgets/src/MuonFitPropertyBrowser.cpp
@@ -41,6 +41,7 @@
 #include <QMessageBox>
 #include <QAction>
 #include <QLayout>
+#include <QSplitter>
 
 namespace {
 Mantid::Kernel::Logger g_log("MuonFitPropertyBrowser");
@@ -149,8 +150,14 @@ void MuonFitPropertyBrowser::init() {
   auto parentLayout = qobject_cast<QVBoxLayout *>(w->layout());
   if (parentLayout) {
     const int index = parentLayout->count() - 2;
-    parentLayout->insertLayout(index, m_additionalLayout);
+    constexpr int stretchFactor = 10; // so these widgets get any extra space
+    parentLayout->insertLayout(index, m_additionalLayout, stretchFactor);
   }
+  m_widgetSplitter = new QSplitter(w);
+  m_widgetSplitter->setOrientation(Qt::Vertical);
+  m_widgetSplitter->setSizePolicy(QSizePolicy::Policy::Expanding,
+                                  QSizePolicy::Policy::Expanding);
+  m_additionalLayout->addWidget(m_widgetSplitter);
 }
 
 /**
@@ -469,8 +476,10 @@ void MuonFitPropertyBrowser::finishAfterSimultaneousFit(
  * @param widget :: [input] Pointer to widget to add
  */
 void MuonFitPropertyBrowser::addExtraWidget(QWidget *widget) {
-  if (m_additionalLayout) {
-    m_additionalLayout->addWidget(widget);
+  widget->setSizePolicy(QSizePolicy::Policy::Expanding,
+                        QSizePolicy::Policy::Expanding);
+  if (m_additionalLayout && m_widgetSplitter) {
+    m_widgetSplitter->addWidget(widget);
   }
 }