diff --git a/src/gtk/bitmap.cpp b/src/gtk/bitmap.cpp
index 5cbff7b1c1..b26bafcff7 100644
--- a/src/gtk/bitmap.cpp
+++ b/src/gtk/bitmap.cpp
@@ -672,6 +672,8 @@ bool wxBitmap::LoadFile( const wxString &name, wxBitmapType type )
     else
 #endif
     {
+        wxUnusedVar(type); // The type is detected automatically by GDK.
+
         UnRef();
         GdkPixbuf* pixbuf = gdk_pixbuf_new_from_file(name.fn_str(), NULL);
         if (pixbuf)
diff --git a/src/gtk/evtloop.cpp b/src/gtk/evtloop.cpp
index 54b216836a..a35be35ab0 100644
--- a/src/gtk/evtloop.cpp
+++ b/src/gtk/evtloop.cpp
@@ -91,10 +91,12 @@ void wxGUIEventLoop::WakeUp()
 
 extern "C"
 {
-static gboolean wx_on_channel_event(GIOChannel * WXUNUSED_UNLESS_DEBUG(channel),
+static gboolean wx_on_channel_event(GIOChannel *channel,
                                     GIOCondition condition,
                                     gpointer data)
 {
+    wxUnusedVar(channel); // Unused if !wxUSE_LOG || !wxDEBUG_LEVEL
+
     wxLogTrace(wxTRACE_EVT_SOURCE,
                "wx_on_channel_event, fd=%d, condition=%08x",
                g_io_channel_unix_get_fd(channel), condition);
diff --git a/src/unix/utilsunx.cpp b/src/unix/utilsunx.cpp
index fa5ee5d7b7..f5380ab137 100644
--- a/src/unix/utilsunx.cpp
+++ b/src/unix/utilsunx.cpp
@@ -1307,6 +1307,8 @@ bool wxAppTraits::CheckForRedirectedIO(wxExecuteData& execData)
 
     return hasIO;
 #else // !HAS_PIPE_INPUT_STREAM
+    wxUnusedVar(execData);
+
     return false;
 #endif // HAS_PIPE_INPUT_STREAM/!HAS_PIPE_INPUT_STREAM
 }