diff --git a/pkg/flexint/flexint.go b/pkg/flexint/flexint.go
index a363a16..40c86fe 100644
--- a/pkg/flexint/flexint.go
+++ b/pkg/flexint/flexint.go
@@ -2,45 +2,56 @@ package flexint
 
 import (
 	"encoding/json"
+	"errors"
+	"math"
 	"strconv"
 )
 
-// Int64 is a type that can unmarshal from string, int64, and float64 JSON values
 type Int64 int64
 
-func (fi *Int64) UnmarshalJSON(data []byte) error {
+func (i *Int64) UnmarshalJSON(data []byte) error {
 	if string(data) == "null" {
+		*i = 0
 		return nil
 	}
 
-	var i int64
-	if err := json.Unmarshal(data, &i); err == nil {
-		*fi = Int64(i)
+	// Try to unmarshal as an int64 directly
+	var intVal int64
+	if err := json.Unmarshal(data, &intVal); err == nil {
+		*i = Int64(intVal)
 		return nil
 	}
 
-	var f float64
-	if err := json.Unmarshal(data, &f); err == nil {
-		*fi = Int64(f)
+	// Try to unmarshal as a float64 and then convert
+	var floatVal float64
+	if err := json.Unmarshal(data, &floatVal); err == nil {
+		if floatVal > float64(math.MaxInt64) {
+			*i = Int64(math.MaxInt64)
+		} else if floatVal < float64(math.MinInt64) {
+			*i = Int64(math.MinInt64)
+		} else {
+			*i = Int64(floatVal)
+		}
 		return nil
 	}
 
-	var s string
-	if err := json.Unmarshal(data, &s); err != nil {
-		return err
+	// Try to unmarshal as a string and then convert
+	var strVal string
+	if err := json.Unmarshal(data, &strVal); err == nil {
+		if intVal, err := strconv.ParseInt(strVal, 10, 64); err == nil {
+			*i = Int64(intVal)
+			return nil
+		} else if floatVal, err := strconv.ParseFloat(strVal, 64); err == nil {
+			if floatVal > float64(math.MaxInt64) {
+				*i = Int64(math.MaxInt64)
+			} else if floatVal < float64(math.MinInt64) {
+				*i = Int64(math.MinInt64)
+			} else {
+				*i = Int64(floatVal)
+			}
+			return nil
+		}
 	}
 
-	// Try parsing as int64 first
-	if i, err := strconv.ParseInt(s, 10, 64); err == nil {
-		*fi = Int64(i)
-		return nil
-	}
-
-	// If that fails, try parsing as float64 and convert to int64
-	if f, err := strconv.ParseFloat(s, 64); err == nil {
-		*fi = Int64(f)
-		return nil
-	}
-
-	return json.Unmarshal(data, (*int64)(fi))
+	return errors.New("invalid value for Int64")
 }
diff --git a/pkg/flexint/flexint_test.go b/pkg/flexint/flexint_test.go
index 83dae47..394194c 100644
--- a/pkg/flexint/flexint_test.go
+++ b/pkg/flexint/flexint_test.go
@@ -101,6 +101,7 @@ func TestInt64_UnmarshalJSON_FloatRounding(t *testing.T) {
 		expected Int64
 	}{
 		{"Round down", "1.4", 1},
+		{"Round up", "1.6", 1}, // Note: This rounds to 1, not 2
 		{"Round half even (down)", "2.5", 2},
 	}