diff --git a/src/lib/platform/PortalInputCapture.cpp b/src/lib/platform/PortalInputCapture.cpp
index b5de16d40..9dbd4f856 100644
--- a/src/lib/platform/PortalInputCapture.cpp
+++ b/src/lib/platform/PortalInputCapture.cpp
@@ -273,7 +273,7 @@ void PortalInputCapture::readClipboardSelection(XdpSession *session) const
 #endif
 }
 
-void PortalInputCapture::handleSelectionTransfer(XdpSession *session, const char *mimeType, uint32_t serial)
+void PortalInputCapture::handleSelectionTransfer(XdpSession *session, const char *mimeType, uint32_t serial) const
 {
 #ifdef HAVE_LIBPORTAL_CLIPBOARD
   if (m_isActive) {
diff --git a/src/lib/platform/PortalInputCapture.h b/src/lib/platform/PortalInputCapture.h
index 001f73555..0871cc0aa 100644
--- a/src/lib/platform/PortalInputCapture.h
+++ b/src/lib/platform/PortalInputCapture.h
@@ -58,7 +58,7 @@ private:
   handleDeactivated(const XdpInputCaptureSession *session, const std::uint32_t activationId, const GVariant *options);
   void handleZonesChanged(XdpInputCaptureSession *session, const GVariant *options);
 
-  void handleSelectionTransfer(XdpSession *session, const char *mimeType, uint32_t serial);
+  void handleSelectionTransfer(XdpSession *session, const char *mimeType, uint32_t serial) const;
   void readClipboardSelection(XdpSession *session) const;
   void claimClipboardOwnership(XdpSession *session) const;