diff --git a/src/ce_main.pas b/src/ce_main.pas
index 7e75daa4..c9bb9791 100644
--- a/src/ce_main.pas
+++ b/src/ce_main.pas
@@ -2187,7 +2187,7 @@ begin
   try
     if fDoc.isNotNil and not fDoc.isTemporary then
       initialDir := fDoc.fileName.extractFileDir;
-    options := [ofAllowMultiSelect, ofEnableSizing];
+    options := options + [ofAllowMultiSelect];
     filter := DdiagFilter;
     if execute then
       for fname in files do
@@ -3403,9 +3403,6 @@ begin
   fFreeProj := nil;
 end;
 
-// TODO-cFileOpenDialog: allow multi selection when possible
-//(open file, add file to project, ...)
-
 // TODO-cprojectsgroup: add a "out of mem" protection in async mode.
 
 procedure TCEMainForm.compileGroup(async: TAsynWait);
diff --git a/src/ce_projgroup.pas b/src/ce_projgroup.pas
index 09ed3a8c..f2505756 100644
--- a/src/ce_projgroup.pas
+++ b/src/ce_projgroup.pas
@@ -527,7 +527,7 @@ var
 begin
   with TOpenDialog.Create(nil) do
   try
-    Options:= [ofAllowMultiSelect, ofEnableSizing];
+    Options:= Options + [ofAllowMultiSelect];
     if not execute then
       exit;
     for fname in Files do
diff --git a/src/ce_projinspect.pas b/src/ce_projinspect.pas
index 24264eaa..ccc82214 100644
--- a/src/ce_projinspect.pas
+++ b/src/ce_projinspect.pas
@@ -288,11 +288,14 @@ begin
 end;
 
 procedure TCEProjectInspectWidget.btnAddFileClick(Sender: TObject);
+var
+  fname: string;
 begin
   if fProject.isNil then exit;
   //
   with TOpenDialog.Create(nil) do
   try
+    options := options + [ofAllowMultiSelect];
     if fLastFileOrFolder.fileExists then
       InitialDir := fLastFileOrFolder.extractFilePath
     else if fLastFileOrFolder.dirExists then
@@ -301,7 +304,8 @@ begin
     if execute then
     begin
       fProject.beginUpdate;
-      fProject.addSource(filename);
+      for fname in Files do
+        fProject.addSource(fname);
       fProject.endUpdate;
     end;
   finally