diff --git a/pain.lua b/pain.lua
index 92a5066..b96b147 100644
--- a/pain.lua
+++ b/pain.lua
@@ -2046,16 +2046,16 @@ end
 
 local checkIfNFP = function(str) --does not check table format, only string format
 	local good = {
-		[0] = true,
-		[1] = true,
-		[2] = true,
-		[3] = true,
-		[4] = true,
-		[5] = true,
-		[6] = true,
-		[7] = true,
-		[8] = true,
-		[9] = true,
+		['0'] = true,
+		['1'] = true,
+		['2'] = true,
+		['3'] = true,
+		['4'] = true,
+		['5'] = true,
+		['6'] = true,
+		['7'] = true,
+		['8'] = true,
+		['9'] = true,
 		a = true,
 		b = true,
 		c = true,