diff --git a/openapi3/schema.go b/openapi3/schema.go
index 4c8df1cba..bc64931de 100644
--- a/openapi3/schema.go
+++ b/openapi3/schema.go
@@ -24,6 +24,14 @@ const (
 	TypeNumber  = "number"
 	TypeObject  = "object"
 	TypeString  = "string"
+
+	// constants for integer formats
+	formatMinInt   = float64(math.MinInt)
+	formatMaxInt   = float64(math.MaxInt)
+	formatMinInt32 = float64(math.MinInt32)
+	formatMaxInt32 = float64(math.MaxInt32)
+	formatMinInt64 = float64(math.MinInt64)
+	formatMaxInt64 = float64(math.MaxInt64)
 )
 
 var (
@@ -1039,6 +1047,35 @@ func (schema *Schema) visitJSONNumber(settings *schemaValidationSettings, value
 		return schema.expectedType(settings, "number, integer")
 	}
 
+	// formats
+	if schema.Format != "" {
+		formatMin := formatMinInt
+		formatMax := formatMaxInt
+		switch schema.Format {
+		case "int32":
+			formatMin = formatMinInt32
+			formatMax = formatMaxInt32
+		case "int64":
+			formatMin = formatMinInt64
+			formatMax = formatMaxInt64
+		}
+		if !(value >= formatMin) || !(value <= formatMax) {
+			if settings.failfast {
+				return errSchema
+			}
+			err := &SchemaError{
+				Value:       value,
+				Schema:      schema,
+				SchemaField: "format",
+				Reason:      fmt.Sprintf("number must be a %s", schema.Format),
+			}
+			if !settings.multiError {
+				return err
+			}
+			me = append(me, err)
+		}
+	}
+
 	// "exclusiveMinimum"
 	if v := schema.ExclusiveMin; v && !(*schema.Min < value) {
 		if settings.failfast {