diff --git a/prosodyctl b/prosodyctl
index a732a73e9..3242218df 100755
--- a/prosodyctl
+++ b/prosodyctl
@@ -937,6 +937,11 @@ function commands.check(arg)
 			print("    Both mod_vcard_legacy and mod_vcard are enabled but they conflict");
 			print("    with each other. Remove one.");
 		end
+		if all_modules:contains("pep") and all_modules:contains("pep_simple") then
+			print("");
+			print("    Both mod_pep_simple and mod_pep are enabled but they conflict");
+			print("    with each other. Remove one.");
+		end
 		for host, host_config in pairs(config) do --luacheck: ignore 213/host
 			if type(rawget(host_config, "storage")) == "string" and rawget(host_config, "default_storage") then
 				print("");