diff --git a/src/contrib/stats/omnet-data-output.cc b/src/contrib/stats/omnet-data-output.cc
index 9903c9ec8..d012d54d7 100644
--- a/src/contrib/stats/omnet-data-output.cc
+++ b/src/contrib/stats/omnet-data-output.cc
@@ -58,7 +58,8 @@ OmnetDataOutput::DoDispose()
 
 inline bool isNumeric(const std::string& s) {
   char *endp;
-  strtod(s.c_str(), &endp);
+  double unused = strtod(s.c_str(), &endp); // declared with warn_unused_result
+  unused = unused; // quiet compiler
   return endp == s.c_str() + s.size();
 }
 
diff --git a/src/devices/emu/emu-net-device.cc b/src/devices/emu/emu-net-device.cc
index 07bc1be87..4764a5e41 100644
--- a/src/devices/emu/emu-net-device.cc
+++ b/src/devices/emu/emu-net-device.cc
@@ -718,6 +718,7 @@ EmuNetDevice::ForwardUp (uint8_t *buf, uint32_t len)
 
     default:
       NS_FATAL_ERROR ("invalid encapsulation mode");
+      protocol = 0; /* quiet compiler */
     }
 
   PacketType packetType;