diff --git a/NEWS b/NEWS
index 3ff4831200..f6ff7bf10c 100644
--- a/NEWS
+++ b/NEWS
@@ -180,6 +180,10 @@ Changed Functionality
   processing input. Specifically in zeek -r scenarios, that is not the wanted
   behaviour.
 
+- The IO loop's poll interval is now correctly reduced from 100 to 10 for
+  live packet sources. This should lower CPU usage for deployments with
+  non-selectable packet sources.
+
 Removed Functionality
 ---------------------
 
diff --git a/src/iosource/Manager.cc b/src/iosource/Manager.cc
index 1cf2d9e599..6b836897b3 100644
--- a/src/iosource/Manager.cc
+++ b/src/iosource/Manager.cc
@@ -402,12 +402,16 @@ void Manager::Register(PktSrc* src)
 	{
 	pkt_src = src;
 
+	Register(src, false);
+
+	// Once we know if the source is live or not, adapt the
+	// poll_interval accordingly.
+	//
+	// Note that src->IsLive() is only valid after calling Register().
 	if ( src->IsLive() )
 		poll_interval = BifConst::io_poll_interval_live;
 	else if ( run_state::pseudo_realtime )
 		poll_interval = 1;
-
-	Register(src, false);
 	}
 
 static std::pair<std::string, std::string> split_prefix(std::string path)