diff --git a/pkg/runtime/init.go b/pkg/runtime/init.go
index 6b9875e8..0414c2b1 100644
--- a/pkg/runtime/init.go
+++ b/pkg/runtime/init.go
@@ -54,7 +54,7 @@ func initRuntime(maxProc int) {
 		}
 	}
 	if maxProc <= 0 {
-		maxProc = 2
+		maxProc = 1
 	}
 	if maxProc > runtime.NumCPU()*2 {
 		maxProc = runtime.NumCPU() * 2