diff --git a/numbaclass.py b/numbaclass.py
index f4b35c0..0b86894 100644
--- a/numbaclass.py
+++ b/numbaclass.py
@@ -18,9 +18,13 @@ def numbaclass(_cls=None, cache=None, writeout=None):
 
     """
 
+    NUMBACLS_BYPASS = 0
+    if (_numbacls_bypass := os.getenv("NUMBACLS_BYPASS")) is not None:
+        NUMBACLS_BYPASS = int(_numbacls_bypass)
+
     # Set defaults flags
     if cache is None:
-        cache = True
+        cache = False
 
     # TODO: File cache (?)
     def cached_MakeNumbaClass(cls, cache):
@@ -65,11 +69,10 @@ def _initcall(*args, **kwargs):
 
         return _initcall
 
-    # TODO: Set as envvar
-    NUMBACLS_BYPASS = 0
-
     def deco_bypass(cls):
-        print("@numbaclass conversion bypassed, NUMBACLS_BYPASS =", NUMBACLS_BYPASS)
+        print(
+            f"@numbaclass conversion bypassed: {cls.__name__}, NUMBACLS_BYPASS = {NUMBACLS_BYPASS}"
+        )
         return cls
 
     if _cls is None: