diff --git a/make-makefiles.py b/make-makefiles.py
index 807ee2f5..0db9c929 100755
--- a/make-makefiles.py
+++ b/make-makefiles.py
@@ -44,7 +44,7 @@
 # be hardwired in.  But this will do for now.
 #
 
-import sys, os, json
+import sys, os, json, glob
 from pathlib import Path
 
 #
@@ -61,6 +61,7 @@ def writefile(fn, str):
 
 INTEGRATION = os.path.dirname(os.path.abspath(sys.argv[0]))
 UNREALENGINE = os.environ["HOME"] + "/UnrealEngine"
+if not os.path.isdir(UNREALENGINE): error("No unreal installed in $HOME/UnrealEngine")
 UNREALBUILDTOOL = f"{UNREALENGINE}/Engine/Binaries/DotNET/UnrealBuildTool/UnrealBuildTool.dll"
 USER = os.environ["USER"]
 
@@ -217,5 +218,5 @@ with open("Integration.code-workspace", "w") as rewritten:
 writefile("Makefile", f"""
 all:
 	(cd luprex ; make)
-	dotnet {UNREALBUILDTOOL} Integration Linux DebugGame -project="{INTEGRATION}/Integration.uproject"
+	dotnet {UNREALBUILDTOOL} IntegrationEditor Linux DebugGame -project="{INTEGRATION}/Integration.uproject" -waitmutex
 """)