diff --git a/binaries/data/mods/public/gui/common/functions_civinfo.js b/binaries/data/mods/public/gui/common/functions_civinfo.js
index 1c0aadc0f0..ab4419a28c 100644
--- a/binaries/data/mods/public/gui/common/functions_civinfo.js
+++ b/binaries/data/mods/public/gui/common/functions_civinfo.js
@@ -21,7 +21,7 @@ function loadCivData(playableOnly = false)
 		// Sanity check
 		for (let prop of ["Code", "Culture", "Name", "Emblem", "History", "Music", "Factions", "CivBonuses",
 		                  "TeamBonuses", "Structures", "StartEntities", "Formations", "AINames","SelectableInGameSetup"])
-			if (!data[prop])
+			if (data[prop] == undefined)
 				error(filename + " doesn't contain " + prop);
 	}
 
diff --git a/binaries/data/mods/public/gui/gamesetup/gamesetup.js b/binaries/data/mods/public/gui/gamesetup/gamesetup.js
index 18cf1ce291..9d15d97431 100644
--- a/binaries/data/mods/public/gui/gamesetup/gamesetup.js
+++ b/binaries/data/mods/public/gui/gamesetup/gamesetup.js
@@ -20,7 +20,7 @@ const g_PlayerColors = g_Settings ? g_Settings.PlayerDefaults.slice(1).map(pData
 const g_RomanNumbers = [undefined, "I", "II", "III", "IV", "V", "VI", "VII", "VIII"];
 
 /**
- * Load playable civs.
+ * Offer users to select playable civs only.
  */
 const g_CivData = loadCivData(true);
 
diff --git a/binaries/data/mods/public/simulation/templates/units/viking_longboat.xml b/binaries/data/mods/public/simulation/templates/units/viking_longboat.xml
index f8086e01f8..c5839dada2 100644
--- a/binaries/data/mods/public/simulation/templates/units/viking_longboat.xml
+++ b/binaries/data/mods/public/simulation/templates/units/viking_longboat.xml
@@ -1,7 +1,7 @@
 <?xml version="1.0" encoding="utf-8"?>
 <Entity parent="template_unit_mechanical_ship_bireme">
   <Identity>
-    <Civ>viking</Civ>
+    <Civ>gaia</Civ>
     <SpecificName>Longboat</SpecificName>
     <History>The first Triremes were built circa 650BC, and by 500BC the Trireme was the most widely used heavy warship of the Greek city-states. In the Trireme the outriggers were now an integral part of the ship's hull. The Trireme also had a partial or full fighting deck above the rowers. The length of the Trireme remained approximately 35-38 meters, and the beam was approximately 3.5 metres. A Trireme carried 170 oarsmen, plus twenty sailors and fourteen marines in Greek navies. The top speed of a Trireme was approximately 11.5 knots. Some Triremes may have been able to reach higher speeds in short bursts. A Trireme travelling from Athens to Mitylene in 427BC made the 350 kilometre trip in only 24 hours, averaging eight knots (14.6 km/h). The Trireme could accelerate much faster than a Bireme or Penteconter, and was much more manoeuvrable. This gave the Trireme an advantage in combat, where higher speed and manoeuvrability meant a better chance of victory.</History>
     <Icon>units/viking_longboat.png</Icon>