diff --git a/src/lte/model/lte-spectrum-phy.h b/src/lte/model/lte-spectrum-phy.h
index b582f4136..8a57a97ce 100644
--- a/src/lte/model/lte-spectrum-phy.h
+++ b/src/lte/model/lte-spectrum-phy.h
@@ -39,6 +39,7 @@
 namespace ns3 {
 
 class LteNetDevice;
+class AntennaModel;
 
 /**
  * \ingroup lte