Undefined reference to gssdp_resource_browser_get_type

[Aurélien Bertron <aurelien bertron insa-lyon fr>]

Hello, I'm trying to make a sample application and I use a resource
browser like this:

gssdp_resource_browser_set_active (GSSDP_RESOURCE_BROWSER (cp), TRUE);

cp is a control point created with gupnp_control_point_new().
When I'm trying to compile, I get this error: "undefined reference to
gssdp_resource_browser_get_type.
I checked in libgssdp/gssdp-resource-browser.h and I found this:

GType
gssdp_resource_browser_get_type (void) G_GNUC_CONST;

So it should be found by linker, do you have any ideas?

Aurélien.