diff --git a/osbuild.py b/osbuild.py
index d546c3f4..e4c5a723 100644
--- a/osbuild.py
+++ b/osbuild.py
@@ -225,7 +225,7 @@ class Assembler:
                 stdout=None if interactive else subprocess.PIPE,
                 stderr=subprocess.STDOUT)
             if r.returncode != 0:
-                raise StageFailed(self.name, r.returncode, r.stdout)
+                raise AssemblerFailed(self.name, r.returncode, r.stdout)
 
             return {
                 "name": self.name,