diff --git a/src/gtk/dataobj.cpp b/src/gtk/dataobj.cpp
index 5e185aba84..00b429c0b4 100644
--- a/src/gtk/dataobj.cpp
+++ b/src/gtk/dataobj.cpp
@@ -108,7 +108,9 @@ wxDataFormatId wxDataFormat::GetType() const
 
 wxString wxDataFormat::GetId() const
 {
-    wxString ret = wxString::FromAscii( gdk_atom_name( m_format ) );
+    gchar* atom_name = gdk_atom_name( m_format );
+    wxString ret = wxString::FromAscii( atom_name );
+    g_free(atom_name);
     return ret;
 }
 
diff --git a/src/gtk1/dataobj.cpp b/src/gtk1/dataobj.cpp
index 1e986e1ce0..7fdc0744fb 100644
--- a/src/gtk1/dataobj.cpp
+++ b/src/gtk1/dataobj.cpp
@@ -108,7 +108,9 @@ wxDataFormatId wxDataFormat::GetType() const
 
 wxString wxDataFormat::GetId() const
 {
-    wxString ret = wxString::FromAscii( gdk_atom_name( m_format ) );
+    gchar* atom_name = gdk_atom_name( m_format );
+    wxString ret = wxString::FromAscii( atom_name );
+    g_free(atom_name);
     return ret;
 }