diff --git a/src/tef/Sidekick_tef.mli b/src/tef/Sidekick_tef.mli
index 28c36807..8766d4a6 100644
--- a/src/tef/Sidekick_tef.mli
+++ b/src/tef/Sidekick_tef.mli
@@ -5,7 +5,7 @@
     profiling probes will emit TEF events.
 
     Profiling is enabled if {!setup} is called, and if
-    the environment variable "TEF" is set to "1" or "true".
+    the environment variable "TRACE" is set to "1" or "true".
     The trace is emitted in the file "trace.json.gz" in the directory
     where the solver is launched; you can open it in
     chrome/chromium at "chrome://tracing".