diff --git a/internal/internal_task_pollers.go b/internal/internal_task_pollers.go
index e655ed48d..fda859ee2 100644
--- a/internal/internal_task_pollers.go
+++ b/internal/internal_task_pollers.go
@@ -1289,6 +1289,9 @@ func reportActivityComplete(
 		switch request.(type) {
 		case *s.RespondActivityTaskCanceledRequest:
 			metricsScope.Counter(metrics.ActivityTaskCanceledCounter).Inc(1)
+			// Also emit failed counter for canceled activities since they represent failures
+			// from a customer monitoring perspective (e.g., heartbeat timeouts)
+			metricsScope.Counter(metrics.ActivityTaskFailedCounter).Inc(1)
 		case *s.RespondActivityTaskFailedRequest:
 			metricsScope.Counter(metrics.ActivityTaskFailedCounter).Inc(1)
 		case *s.RespondActivityTaskCompletedRequest:
@@ -1342,6 +1345,9 @@ func reportActivityCompleteByID(
 		switch request.(type) {
 		case *s.RespondActivityTaskCanceledByIDRequest:
 			metricsScope.Counter(metrics.ActivityTaskCanceledByIDCounter).Inc(1)
+			// Also emit failed counter for canceled activities since they represent failures
+			// from a customer monitoring perspective (e.g., heartbeat timeouts)
+			metricsScope.Counter(metrics.ActivityTaskFailedByIDCounter).Inc(1)
 		case *s.RespondActivityTaskFailedByIDRequest:
 			metricsScope.Counter(metrics.ActivityTaskFailedByIDCounter).Inc(1)
 		case *s.RespondActivityTaskCompletedByIDRequest: