diff --git a/joosc.py b/joosc.py
index fad79f13709bbcc4b045048c1b65d1256848ccee..ab692eb617d0384032bf4ec444059c76f8f2066f 100644
--- a/joosc.py
+++ b/joosc.py
@@ -5,7 +5,7 @@ from os.path import isfile, join
 
 from Scanning import scan
 from Parsing import parse
-from AstBuilding import astBuild, buildEnvAndLink, disamiguateAndTypeChecking
+from AstBuilding import astBuild, buildEnvAndLink, disamiguateAndTypeChecking, reachabilityChecking
 import Weeding
 
 
@@ -60,6 +60,11 @@ def main():
     except Exception as e:
         return 42
 
+    try:
+        reachabilityChecking(ASTs)
+    except Exception as e:
+        return 42
+
     return 0