diff --git a/src/fileformats/file_import_export.cpp b/src/fileformats/file_import_export.cpp
index 8583ea3c8..d0dec615d 100644
--- a/src/fileformats/file_import_export.cpp
+++ b/src/fileformats/file_import_export.cpp
@@ -1,7 +1,7 @@
 /*
  *    Copyright 2012, 2013 Pete Curtis
  *    Copyright 2013, 2014 Thomas Schöps
- *    Copyright 2013-2020 Kai Pastor
+ *    Copyright 2013-2020, 2024 Kai Pastor
  *
  *    This file is part of OpenOrienteering.
  *
@@ -21,6 +21,7 @@
 
 #include "file_import_export.h"
 
+#include <algorithm>
 #include <exception>
 #include <memory>
 #include <utility>
@@ -84,6 +85,13 @@ void ImportExport::setOption(const QString& name, const QVariant& value)
 }
 
 
+void ImportExport::addWarningOnce(const QString& str)
+{
+	if (std::find(warnings_.begin(), warnings_.end(), str) == warnings_.end())
+		warnings_.emplace_back(str);
+}
+
+
 // ### Importer ###
 
 Importer::~Importer() = default;
diff --git a/src/fileformats/file_import_export.h b/src/fileformats/file_import_export.h
index 6097f8fa7..9dc388c8d 100644
--- a/src/fileformats/file_import_export.h
+++ b/src/fileformats/file_import_export.h
@@ -1,6 +1,6 @@
 /*
  *    Copyright 2012, 2013 Pete Curtis
- *    Copyright 2018 Kai Pastor
+ *    Copyright 2018, 2024 Kai Pastor
  *
  *    This file is part of OpenOrienteering.
  *
@@ -112,6 +112,13 @@ class ImportExport
 	 */
 	void addWarning(const QString& str) { warnings_.emplace_back(str); }
 	
+	/**
+	 * Adds a string to the current list of warnings if not yet in the list.
+	 * 
+	 * The provided message should be translated.
+	 */
+	void addWarningOnce(const QString& str);
+	
 	/**
 	 * Returns the current list of warnings collected by this object.
 	 */
diff --git a/src/fileformats/ocd_file_import.cpp b/src/fileformats/ocd_file_import.cpp
index 0fac5b1c2..788d56b0f 100644
--- a/src/fileformats/ocd_file_import.cpp
+++ b/src/fileformats/ocd_file_import.cpp
@@ -2163,6 +2163,16 @@ void OcdFileImport::fillPathCoords(OcdImportedPathObject *object, bool is_area,
 	{
 		object->coords[i] = convertOcdPoint(ocd_points[i]);
 		setPointFlags(object, i, is_area, ocd_points[i]);
+		if (ocd_points[i].x & Ocd::OcdPoint32::FlagGap)
+		{
+			// Virtual gaps are not supported
+			addWarningOnce(tr("Virtual gaps in line objects are not supported."));
+		}
+		if (ocd_points[i].x & Ocd::OcdPoint32::FlagLeft || ocd_points[i].y & Ocd::OcdPoint32::FlagRight)
+		{
+			// Double line gaps are not supported
+			addWarningOnce(tr("Gaps in double line objects are not supported."));
+		}
 	}
 	
 	// For path objects, create closed parts where the position of the last point is equal to that of the first point
diff --git a/src/fileformats/ocd_types.h b/src/fileformats/ocd_types.h
index f872e9a39..b3da02e41 100644
--- a/src/fileformats/ocd_types.h
+++ b/src/fileformats/ocd_types.h
@@ -1,5 +1,5 @@
 /*
- *    Copyright 2013, 2015-2019 Kai Pastor
+ *    Copyright 2013, 2015-2019, 2024 Kai Pastor
  *
  *    This file is part of OpenOrienteering.
  *
@@ -231,7 +231,8 @@ namespace Ocd
 		{
 			FlagCtl1 = 0x01,
 			FlagCtl2 = 0x02,
-			FlagLeft = 0x04
+			FlagLeft = 0x04,
+			FlagGap  = 0x08
 		};
 		
 		// Flags in Y coordinate