diff --git a/vala/valainterface.vala b/vala/valainterface.vala
index e3615c1..d726841 100644
--- a/vala/valainterface.vala
+++ b/vala/valainterface.vala
@@ -263,20 +263,32 @@ public class Vala.Interface : Typesymbol {
 	 */
 	public string! get_lower_case_csuffix () {
 		if (lower_case_csuffix == null) {
-			lower_case_csuffix = camel_case_to_lower_case (name);
-
-			// remove underscores in some cases to avoid conflicts of type macros
-			if (lower_case_csuffix.has_prefix ("type_")) {
-				lower_case_csuffix = "type" + lower_case_csuffix.offset ("type_".len ());
-			} else if (lower_case_csuffix.has_prefix ("is_")) {
-				lower_case_csuffix = "is" + lower_case_csuffix.offset ("is_".len ());
-			}
-			if (lower_case_csuffix.has_suffix ("_class")) {
-				lower_case_csuffix = lower_case_csuffix.substring (0, lower_case_csuffix.len () - "_class".len ()) + "class";
-			}
+			lower_case_csuffix = get_default_lower_case_csuffix ();
 		}
 		return lower_case_csuffix;
 	}
+
+	/**
+	 * Returns default string to be prepended to the name of members of this
+	 * interface when used in C code.
+	 *
+	 * @return the suffix to be used in C code
+	 */
+	public string! get_default_lower_case_csuffix () {
+		string result = camel_case_to_lower_case (name);
+
+		// remove underscores in some cases to avoid conflicts of type macros
+		if (result.has_prefix ("type_")) {
+			result = "type" + result.offset ("type_".len ());
+		} else if (result.has_prefix ("is_")) {
+			result = "is" + result.offset ("is_".len ());
+		}
+		if (result.has_suffix ("_class")) {
+			result = result.substring (0, result.len () - "_class".len ()) + "class";
+		}
+
+		return result;
+	}
 	
 	/**
 	 * Sets the string to be prepended to the name of members of this
@@ -389,6 +401,9 @@ public class Vala.Interface : Typesymbol {
 				add_cheader_filename (filename);
 			}
 		}
+		if (a.has_argument ("lower_case_csuffix")) {
+			lower_case_csuffix = a.get_string ("lower_case_csuffix");
+		}
 	}
 
 	private void process_dbus_interface_attribute (Attribute! a) {
diff --git a/vala/valainterfacewriter.vala b/vala/valainterfacewriter.vala
index 10c8e93..c7d7ddf 100644
--- a/vala/valainterfacewriter.vala
+++ b/vala/valainterfacewriter.vala
@@ -240,7 +240,11 @@ public class Vala.InterfaceWriter : CodeVisitor {
 				cheaders = "%s,%s".printf (cheaders, cheader);
 			}
 		}
-		write_string ("[CCode (cheader_filename = \"%s\")]".printf (cheaders));
+		write_string ("[CCode (cheader_filename = \"%s\"".printf (cheaders));
+		if (iface.get_lower_case_csuffix () != iface.get_default_lower_case_csuffix ())
+			write_string (", lower_case_csuffix = \"%s\"".printf (iface.get_lower_case_csuffix ()));
+
+		write_string (")]");
 		write_newline ();
 
 		write_indent ();
diff --git a/vapi/packages/gstreamer-interfaces-0.10/gstreamer-interfaces-0.10.metadata b/vapi/packages/gstreamer-interfaces-0.10/gstreamer-interfaces-0.10.metadata
index 4602013..4abc3ea 100644
--- a/vapi/packages/gstreamer-interfaces-0.10/gstreamer-interfaces-0.10.metadata
+++ b/vapi/packages/gstreamer-interfaces-0.10/gstreamer-interfaces-0.10.metadata
@@ -23,4 +23,4 @@ GstNavigation cheader_filename="gst/interfaces/navigation.h"
 GstPropertyProbe cheader_filename="gst/interfaces/propertyprobe.h"
 GstTuner cheader_filename="gst/interfaces/tunerchannel.h"
 GstVideoOrientation cheader_filename="gst/interfaces/videoorientation.h"
-GstXOverlay cheader_filename="gst/interfaces/xoverlay.h"
+GstXOverlay cheader_filename="gst/interfaces/xoverlay.h" lower_case_csuffix="x_overlay"
diff --git a/vapigen/valagidlparser.vala b/vapigen/valagidlparser.vala
index 1b9cae7..4fbd575 100644
--- a/vapigen/valagidlparser.vala
+++ b/vapigen/valagidlparser.vala
@@ -917,6 +917,8 @@ public class Vala.GIdlParser : CodeVisitor {
 					var nv = attr.split ("=", 2);
 					if (nv[0] == "cheader_filename") {
 						iface.add_cheader_filename (eval (nv[1]));
+					} else if (nv[0] == "lower_case_csuffix") {
+						iface.set_lower_case_csuffix (eval (nv[1]));
 					}
 				}
 			}