Now matches exact type given, rather than any base preconditions from which it may derive

src/Discord.Net.Commands/Info/CommandInfo.cs

@@ -64,7 +64,7 @@ namespace Discord.Commands
         }
 
         public TPrecondition GetPrecondition<TPrecondition>() where TPrecondition : PreconditionAttribute =>
-            Preconditions.FirstOrDefault(x => x is TPrecondition) as TPrecondition;
+            Preconditions.FirstOrDefault(x => x.GetType() == typeof(TPrecondition)) as TPrecondition;
 
         public async Task<PreconditionResult> CheckPreconditionsAsync(ICommandContext context, IDependencyMap map = null)
         {

src/Discord.Net.Commands/Info/ModuleInfo.cs

@@ -21,7 +21,7 @@ namespace Discord.Commands
         public bool IsSubmodule => Parent != null;
 
         public TPrecondition GetPrecondition<TPrecondition>() where TPrecondition : PreconditionAttribute =>
-            Preconditions.FirstOrDefault(x => x is TPrecondition) as TPrecondition;
+            Preconditions.FirstOrDefault(x => x.GetType() == typeof(TPrecondition)) as TPrecondition;
 
         internal ModuleInfo(ModuleBuilder builder, CommandService service, ModuleInfo parent = null)
         {