diff --git a/backends/arm/arm_backend.py b/backends/arm/arm_backend.py
index 979a2464840..d695aec2fd8 100644
--- a/backends/arm/arm_backend.py
+++ b/backends/arm/arm_backend.py
@@ -50,6 +50,7 @@ def __init__(self):
         self.output_format = None
         self.path_for_intermediates = None
         self.tosa_version = None
+        self.tosa_spec = None
         self.input_order = None
 
     def ethosu_compile_spec(