diff --git a/src/libxl/libxl_capabilities.h b/src/libxl/libxl_capabilities.h
index 9a7c8bf636..9efb836429 100644
--- a/src/libxl/libxl_capabilities.h
+++ b/src/libxl/libxl_capabilities.h
@@ -50,4 +50,5 @@ libxlMakeDomainCapabilities(virDomainCapsPtr domCaps,
                             size_t nfirmwares);
 
 int
-libxlDomainGetEmulatorType(const virDomainDef *def);
+libxlDomainGetEmulatorType(const virDomainDef *def)
+    G_GNUC_NO_INLINE;
diff --git a/tests/libxlmock.c b/tests/libxlmock.c
index 60e6b78129..a36ca135f6 100644
--- a/tests/libxlmock.c
+++ b/tests/libxlmock.c
@@ -30,6 +30,7 @@
 
 # include "virfile.h"
 # include "virsocket.h"
+# include "libxl/libxl_capabilities.h"
 
 VIR_MOCK_IMPL_RET_VOID(xs_daemon_open,
                        struct xs_handle *)
@@ -123,4 +124,10 @@ VIR_MOCK_IMPL_RET_ARGS(stat, int,
     return real_stat(path, sb);
 }
 
+int
+libxlDomainGetEmulatorType(const virDomainDef *def G_GNUC_UNUSED)
+{
+    return LIBXL_DEVICE_MODEL_VERSION_QEMU_XEN;
+}
+
 #endif /* WITH_LIBXL && WITH_YAJL */