diff --git a/Source/Core/Editing/ThingsFilter.cs b/Source/Core/Editing/ThingsFilter.cs
index a316f68e..9fdb5a35 100644
--- a/Source/Core/Editing/ThingsFilter.cs
+++ b/Source/Core/Editing/ThingsFilter.cs
@@ -290,7 +290,7 @@ namespace CodeImp.DoomBuilder.Editing
 			foreach(Thing t in General.Map.Map.Things)
 			{
 				bool qualifies = true;
-				
+
 				// Get thing info
 				ThingTypeInfo ti = General.Map.Data.GetThingInfo(t.Type);
 				
@@ -321,7 +321,11 @@ namespace CodeImp.DoomBuilder.Editing
 					{
 						if(t.Flags.ContainsKey(s))
 						{
-							qualifies = (t.Flags[s] == true);
+							if(t.Flags[s] == false)
+							{
+								qualifies = false;
+								break;
+							}
 						}
 						else
 						{
@@ -338,7 +342,13 @@ namespace CodeImp.DoomBuilder.Editing
 					foreach(string s in forbiddenfields)
 					{
 						if(t.Flags.ContainsKey(s))
-							qualifies = (t.Flags[s] == false);
+						{
+							if(t.Flags[s] == true)
+							{
+								qualifies = false;
+								break;
+							}
+						}
 					}
 				}
 				
@@ -350,7 +360,11 @@ namespace CodeImp.DoomBuilder.Editing
 					{
 						if(t.Fields.ContainsKey(kv.Key))
 						{
-							qualifies = (t.Fields[kv.Key].Type == kv.Value.Type) && (t.Fields[kv.Key].Value.Equals(kv.Value.Value));
+							if(!((t.Fields[kv.Key].Type == kv.Value.Type) && (t.Fields[kv.Key].Value.Equals(kv.Value.Value))))
+							{
+								qualifies = false;
+								break;
+							}
 						}
 						else
 						{
diff --git a/Source/Plugins/BuilderModes/ClassicModes/EditSelectionMode.cs b/Source/Plugins/BuilderModes/ClassicModes/EditSelectionMode.cs
index 46fe73b0..36bfd9e9 100644
--- a/Source/Plugins/BuilderModes/ClassicModes/EditSelectionMode.cs
+++ b/Source/Plugins/BuilderModes/ClassicModes/EditSelectionMode.cs
@@ -1272,6 +1272,7 @@ namespace CodeImp.DoomBuilder.BuilderModes
 				// Update cached values
 				General.Map.Data.UpdateUsedTextures();
 				General.Map.Map.Update();
+				General.Map.ThingsFilter.Update();
 				
 				// Make normal selection
 				General.Map.Map.ClearAllSelected();