diff --git a/arduino-core/src/processing/app/Sketch.java b/arduino-core/src/processing/app/Sketch.java
index 6c417403ec9..41482bb92ac 100644
--- a/arduino-core/src/processing/app/Sketch.java
+++ b/arduino-core/src/processing/app/Sketch.java
@@ -22,6 +22,8 @@ public class Sketch {
   public static final List<String> OTHER_ALLOWED_EXTENSIONS = Arrays.asList("c", "cpp", "h", "hh", "hpp", "s");
   public static final List<String> EXTENSIONS = Stream.concat(SKETCH_EXTENSIONS.stream(), OTHER_ALLOWED_EXTENSIONS.stream()).collect(Collectors.toList());
 
+  private final File initialFile;
+
   /**
    * folder that contains this sketch
    */
@@ -50,6 +52,7 @@ public int compare(SketchFile x, SketchFile y) {
    *          Any file inside the sketch directory.
    */
   Sketch(File file) throws IOException {
+    initialFile = file;
     folder = file.getParentFile();
     files = listSketchFiles(true);
   }
@@ -143,6 +146,13 @@ public int getCodeCount() {
     return files.size();
   }
 
+  /**
+   * Returns the initial File used to initialize this Sketch
+   */
+  public File getInitialFile() {
+    return initialFile;
+  }
+
   public SketchFile[] getFiles() {
     return files.toArray(new SketchFile[0]);
   }
diff --git a/arduino-core/src/processing/app/SketchFile.java b/arduino-core/src/processing/app/SketchFile.java
index f1341653b57..c9af78a60ca 100644
--- a/arduino-core/src/processing/app/SketchFile.java
+++ b/arduino-core/src/processing/app/SketchFile.java
@@ -95,7 +95,8 @@ public SketchFile(Sketch sketch, File file) {
     this.sketch = sketch;
     this.file = file;
     FileUtils.SplitFile split = FileUtils.splitFilename(file);
-    this.primary = split.basename.equals(sketch.getFolder().getName())
+    this.primary = (file.equals(sketch.getInitialFile())
+        || split.basename.equals(sketch.getFolder().getName()))
         && Sketch.SKETCH_EXTENSIONS.contains(split.extension);
   }