diff --git a/api/prometheus/v1/api.go b/api/prometheus/v1/api.go
index 1ff4402..b98c075 100644
--- a/api/prometheus/v1/api.go
+++ b/api/prometheus/v1/api.go
@@ -327,7 +327,7 @@ type Alert struct {
 	Annotations model.LabelSet
 	Labels      model.LabelSet
 	State       AlertState
-	Value       float64
+	Value       string
 }
 
 // TargetsResult contains the result from querying the targets endpoint.
diff --git a/api/prometheus/v1/api_test.go b/api/prometheus/v1/api_test.go
index 0e24b49..9a58272 100644
--- a/api/prometheus/v1/api_test.go
+++ b/api/prometheus/v1/api_test.go
@@ -493,7 +493,7 @@ func TestAPIs(t *testing.T) {
 											"severity":  "page",
 										},
 										"state": "firing",
-										"value": 1,
+										"value": "1e+00",
 									},
 								},
 								"annotations": map[string]interface{}{
@@ -537,7 +537,7 @@ func TestAPIs(t *testing.T) {
 											"severity":  "page",
 										},
 										State: AlertStateFiring,
-										Value: 1,
+										Value: "1e+00",
 									},
 								},
 								Annotations: model.LabelSet{