diff --git a/xwords4/relay/cidlock.cpp b/xwords4/relay/cidlock.cpp
index 3ef881399..dfa03887f 100644
--- a/xwords4/relay/cidlock.cpp
+++ b/xwords4/relay/cidlock.cpp
@@ -80,7 +80,7 @@ CidLock::print_claimed( const char* caller )
         if ( 0 == info->GetOwner() ) {
             ++unclaimed;
         } else {
-            str. printf( "%d,", info->GetCid() );
+            str.printf( "%d,", info->GetCid() );
         }
     }
     str.printf( " (plus %d unclaimed.)", unclaimed );
diff --git a/xwords4/relay/devmgr.cpp b/xwords4/relay/devmgr.cpp
index f4ccbe616..fbc84b43e 100644
--- a/xwords4/relay/devmgr.cpp
+++ b/xwords4/relay/devmgr.cpp
@@ -139,7 +139,7 @@ DevMgr::getKnownDevices( vector<DevIDRelay>& devids )
 // it, so that as much work as possible is done on the calling thread without
 // holding up more important stuff.
 void
-DevMgr::printDevices( StrWPF& str, vector<DevIDRelay> devids )
+DevMgr::printDevices( StrWPF& str, const vector<DevIDRelay>& devids )
 {
     map<uint32_t, DevIDRelay> agedDevs;
     {
diff --git a/xwords4/relay/devmgr.h b/xwords4/relay/devmgr.h
index 4743e2815..69c640488 100644
--- a/xwords4/relay/devmgr.h
+++ b/xwords4/relay/devmgr.h
@@ -37,7 +37,7 @@ class DevMgr {
 
     /* Called from ctrl port */
     void printDevices( StrWPF& str, 
-                       vector<DevIDRelay> devids /* empty means all */ );
+                       const vector<DevIDRelay>& devids /* empty means all */ );
     int forgetDevices( vector<DevIDRelay>& devids );
     void getKnownDevices( vector<DevIDRelay>& devids );