diff --git a/pkg/mining/circuit_breaker.go b/pkg/mining/circuit_breaker.go
index d101e35..f107efa 100644
--- a/pkg/mining/circuit_breaker.go
+++ b/pkg/mining/circuit_breaker.go
@@ -1,7 +1,6 @@
 package mining
 
 import (
-	"errors"
 	"sync"
 	"time"
 
@@ -68,7 +67,8 @@ type CircuitBreaker struct {
 }
 
 // ErrCircuitOpen is returned when the circuit is open
-var ErrCircuitOpen = errors.New("circuit breaker is open")
+// if err == ErrCircuitOpen { /* fallback to cached result */ }
+var ErrCircuitOpen = NewMiningError(ErrCodeServiceUnavailable, "circuit breaker is open")
 
 // NewCircuitBreaker creates a new circuit breaker
 func NewCircuitBreaker(name string, config CircuitBreakerConfig) *CircuitBreaker {