diff --git a/src/main/resources/assets/computercraft/lua/rom/apis/gps b/src/main/resources/assets/computercraft/lua/rom/apis/gps
index 9f7cb5fd0..5fabbd0dd 100644
--- a/src/main/resources/assets/computercraft/lua/rom/apis/gps
+++ b/src/main/resources/assets/computercraft/lua/rom/apis/gps
@@ -103,7 +103,7 @@ function locate( _nTimeout, _bDebug )
 			local sSide, sChannel, sReplyChannel, tMessage, nDistance = p1, p2, p3, p4, p5
 			if sSide == sModemSide and sChannel == os.getComputerID() and sReplyChannel == CHANNEL_GPS and nDistance then
 				-- Received the correct message from the correct modem: use it to determine position
-				if type(tMessage) == "table" and #tMessage == 3 then
+				if type(tMessage) == "table" and #tMessage == 3 and type(tMessage[1]) == "number" and type(tMessage[2]) == "number" and type(tMessage[3]) == "number" then
 					local tFix = { vPosition = vector.new( tMessage[1], tMessage[2], tMessage[3] ), nDistance = nDistance }
 					if _bDebug then
 						print( tFix.nDistance.." metres from "..tostring( tFix.vPosition ) )
diff --git a/src/main/resources/assets/computercraft/lua/rom/apis/vector b/src/main/resources/assets/computercraft/lua/rom/apis/vector
index e5d1a981a..29b10e500 100644
--- a/src/main/resources/assets/computercraft/lua/rom/apis/vector
+++ b/src/main/resources/assets/computercraft/lua/rom/apis/vector
@@ -76,9 +76,9 @@ local vmetatable = {
 
 function new( x, y, z )
 	local v = {
-		x = x or 0,
-		y = y or 0,
-		z = z or 0
+		x = type(x) == "number" and x or 0,
+		y = type(y) == "number" and y or 0,
+		z = type(z) == "number" and z or 0
 	}
 	setmetatable( v, vmetatable )
 	return v