diff --git a/src/classes/PMusrWebCanvas.cpp b/src/classes/PMusrWebCanvas.cpp
index 58de4655..405bdf8d 100644
--- a/src/classes/PMusrWebCanvas.cpp
+++ b/src/classes/PMusrWebCanvas.cpp
@@ -1005,12 +1005,31 @@ Bool_t PMusrWebCanvas::Show(const std::string &where)
  * <p>Derives the base name (no extension) under which this plot block's
  * graphics are saved by default, mirroring the --png/--pdf/... batch export
  * naming: <msr-base>_<plotNo>[_F]. Used both by the batch export and as the
- * suggested name offered to the interactive "Save graphics" dialog.
+ * starting point of the interactive "Save graphics" naming.
  *
  * \return the base name, or empty if the msr-file name carries neither a
  *         ".msr" nor a ".mlog" extension to replace
  */
 std::string PMusrWebCanvas::DefaultGraphicsBaseName() const
+{
+  return GraphicsBaseName(fPlotNumber);
+}
+
+//--------------------------------------------------------------------------
+// GraphicsBaseName (private)
+//--------------------------------------------------------------------------
+/**
+ * <p>Builds the graphics base name (no extension) of the given plot index:
+ * <msr-base>_<plotNo>[_F], the "_F" being added in the Fourier representation.
+ *
+ * \param plotNumber the index to put into the name; normally the number of the
+ *        PLOT block, the interactive save counts it up to avoid overwriting
+ *        (see SaveGraphicsForDownload())
+ *
+ * \return the base name, or empty if the msr-file name carries neither a
+ *         ".msr" nor a ".mlog" extension to replace
+ */
+std::string PMusrWebCanvas::GraphicsBaseName(Int_t plotNumber) const
 {
   TString str(fMsrFileName.c_str());
   Int_t idx = -1;
@@ -1027,9 +1046,9 @@ std::string PMusrWebCanvas::DefaultGraphicsBaseName() const
 
   Char_t ext[64];
   if (fMode.IsFourier())
-    snprintf(ext, sizeof(ext), "_%d_F", fPlotNumber);
+    snprintf(ext, sizeof(ext), "_%d_F", plotNumber);
   else
-    snprintf(ext, sizeof(ext), "_%d", fPlotNumber);
+    snprintf(ext, sizeof(ext), "_%d", plotNumber);
   str.Replace(idx, size, ext, strlen(ext));
 
   return str.Data();
@@ -1071,6 +1090,10 @@ Bool_t PMusrWebCanvas::SaveGraphics(const std::string &graphicsFormat)
  * the file is handed to the browser as a normal download, so the browser's
  * own save dialog (or download folder) decides where it ends up.
  *
+ * <p>Saving the same view repeatedly never overwrites what is already there:
+ * as in the root6 musrview, the index of the default name is counted up until
+ * a free one is found, i.e. <msr-base>_0.png, <msr-base>_1.png, ...
+ *
  * \param graphicsFormat extension such as "png", "pdf", "eps", ...
  * \param panels which of the title/parameters/theory/run-info blocks to
  *        include, mirroring the interactive view's current panel visibility
@@ -1082,15 +1105,23 @@ Bool_t PMusrWebCanvas::SaveGraphics(const std::string &graphicsFormat)
 Bool_t PMusrWebCanvas::SaveGraphicsForDownload(const std::string &graphicsFormat, const PanelVisibility &panels,
                                                 std::string &relUrl)
 {
-  const std::string base = DefaultGraphicsBaseName();
-  if (base.empty()) {
+  if (DefaultGraphicsBaseName().empty()) {
     fLastError = "msr-file name '" + fMsrFileName + "' is invalid.";
     return false;
   }
 
-  // ignore any directory the msr-file name may carry: the download is always
-  // served out of the current working directory (see Show()/currentdir/)
-  const std::string fileName = std::string(gSystem->BaseName(base.c_str())) + "." + graphicsFormat;
+  // Ignore any directory the msr-file name may carry: the download is always
+  // served out of the current working directory (see Show()/currentdir/).
+  // Starting from the number of the PLOT block, count the index up as long as
+  // the resulting file already exists, so that saving a view twice gives a
+  // second file rather than replacing the first one.
+  std::string fileName;
+  for (Int_t idx = fPlotNumber; ; idx++) {
+    const std::string base = GraphicsBaseName(idx);
+    fileName = std::string(gSystem->BaseName(base.c_str())) + "." + graphicsFormat;
+    if (gSystem->AccessPathName(fileName.c_str()) == kTRUE) // does not exist yet
+      break;
+  }
 
   if (!RenderGraphics(fileName, panels))
     return false;
diff --git a/src/include/PMusrWebCanvas.h b/src/include/PMusrWebCanvas.h
index e42b75f0..288b7f6b 100644
--- a/src/include/PMusrWebCanvas.h
+++ b/src/include/PMusrWebCanvas.h
@@ -143,6 +143,8 @@ class PMusrWebCanvas
     /// The name/location that graphics files are derived from by default,
     /// without extension.
     std::string DefaultGraphicsBaseName() const;
+    /// The graphics base name (without extension) carrying the given index.
+    std::string GraphicsBaseName(Int_t plotNumber) const;
     /// Writes the currently shown data as ascii.
     Bool_t ExportData(const std::string &fileName);