diff --git a/cmd/syncthing/main.go b/cmd/syncthing/main.go
index 98175f80f..3b9cfe59b 100644
--- a/cmd/syncthing/main.go
+++ b/cmd/syncthing/main.go
@@ -173,7 +173,7 @@ type serveOptions struct {
 	DebugGUIAssetsDir         string        `placeholder:"PATH" help:"Directory to load GUI assets from" env:"STGUIASSETS"`
 	DebugPerfStats            bool          `env:"STPERFSTATS" help:"Write running performance statistics to perf-$pid.csv (Unix only)"`
 	DebugProfileBlock         bool          `env:"STBLOCKPROFILE" help:"Write block profiles to block-$pid-$timestamp.pprof every 20 seconds"`
-	DebugProfileCPU           bool          `help:"Write a CPU profile to cpu-$pid.pprof on exit" env:"CPUPROFILE"`
+	DebugProfileCPU           bool          `help:"Write a CPU profile to cpu-$pid.pprof on exit" env:"STCPUPROFILE"`
 	DebugProfileHeap          bool          `env:"STHEAPPROFILE" help:"Write heap profiles to heap-$pid-$timestamp.pprof each time heap usage increases"`
 	DebugProfilerListen       string        `placeholder:"ADDR" env:"STPROFILER" help:"Network profiler listen address"`
 	DebugResetDatabase        bool          `name:"reset-database" help:"Reset the database, forcing a full rescan and resync"`