diff --git a/os/gctx/gctx.go b/os/gctx/gctx.go
index 02a8d6083..686ed8aad 100644
--- a/os/gctx/gctx.go
+++ b/os/gctx/gctx.go
@@ -33,6 +33,9 @@ func init() {
 	i := 0
 	for _, s := range os.Environ() {
 		i = strings.IndexByte(s, '=')
+		if i == -1 {
+			continue
+		}
 		m[s[0:i]] = s[i+1:]
 	}
 	// OpenTelemetry from environments.