diff --git a/logpyle/__init__.py b/logpyle/__init__.py
index 78b0b85..810dfc8 100644
--- a/logpyle/__init__.py
+++ b/logpyle/__init__.py
@@ -1701,6 +1701,12 @@ def add_simulation_quantities(mgr: LogManager) -> None:
     mgr.add_quantity(Timestep())
 
 
+def _get_env_vars() -> str:
+    """Return a string containing all environment variables."""
+    from os import environ
+    return "\n".join(f"{key}={value}" for key, value in environ.items())
+
+
 def add_run_info(mgr: LogManager) -> None:
     """Add generic run metadata, such as command line, host, and time."""
 
@@ -1717,6 +1723,7 @@ def add_run_info(mgr: LogManager) -> None:
     from time import localtime, strftime, time
     mgr.set_constant("date", strftime("%a, %d %b %Y %H:%M:%S %Z", localtime()))
     mgr.set_constant("unixtime", time())
+    mgr.set_constant("env", _get_env_vars())
 
 
 class MemoryHwm(PostLogQuantity):
diff --git a/test/test_gather.py b/test/test_gather.py
index 4acb998..211c1e9 100644
--- a/test/test_gather.py
+++ b/test/test_gather.py
@@ -11,7 +11,7 @@ def __call__(self) -> int:
         return 15
 
 
-def create_log(filename: str):
+def create_log(filename: str) -> None:
     logmgr = LogManager(filename, "wo")
 
     # Generic run metadata, such as command line, host, and time
@@ -40,7 +40,7 @@ def create_log(filename: str):
     logmgr.close()
 
 
-def test_auto_gather_single():
+def test_auto_gather_single() -> None:
     # run example
     create_log("log.sqlite")
     assert os.path.exists("log.sqlite"), "The logging file was not generated."
@@ -77,7 +77,7 @@ def test_auto_gather_single():
     print("Constant data:")
     result = [row[0] for row in cur.description]
     print(result)
-    assert len(result) == 11
+    assert len(result) == 12
 
     db = make_wrapped_db(["log.sqlite"], mangle=True, interactive=False)
     cur = db.q("select $fifteen")
@@ -91,7 +91,7 @@ def test_auto_gather_single():
     os.remove("log.sqlite")
 
 
-def test_auto_gather_multi():
+def test_auto_gather_multi() -> None:
     # run example
     def is_unique_filename(str: str):
         return str.startswith("multi-log")
@@ -142,7 +142,7 @@ def is_unique_filename(str: str):
     print("Constant data:")
     result = [row[0] for row in cur.description]
     print(result)
-    assert len(result) == 11
+    assert len(result) == 12
 
     # teardown test
     for f in filenames: