diff --git a/eth/tracers/api.go b/eth/tracers/api.go
index 36a2785b6f..198d8623e2 100644
--- a/eth/tracers/api.go
+++ b/eth/tracers/api.go
@@ -74,6 +74,8 @@ const (
 
 var defaultBorTraceEnabled = newBoolPtr(false)
 
+var allowIOTracing = false // Change this to true to enable IO tracing for debugging
+
 // Backend interface provides the common API services (that are provided by
 // both full and light clients) with access to necessary functions.
 type Backend interface {
@@ -719,7 +721,7 @@ func (api *API) traceBlock(ctx context.Context, block *types.Block, config *Trac
 	}
 
 	ioflag := defaultIOFlag
-	if config != nil && config.IOFlag != nil {
+	if allowIOTracing && config != nil && config.IOFlag != nil {
 		ioflag = *config.IOFlag
 	}
 
diff --git a/eth/tracers/api_test.go b/eth/tracers/api_test.go
index 653b50d349..b7207b5b81 100644
--- a/eth/tracers/api_test.go
+++ b/eth/tracers/api_test.go
@@ -449,6 +449,8 @@ func TestIOdump(t *testing.T) {
 		}
 	}))
 
+	allowIOTracing = true
+
 	ioflag := new(bool)
 
 	*ioflag = true