diff --git a/marshal.go b/marshal.go
index 671da55..cd9128c 100644
--- a/marshal.go
+++ b/marshal.go
@@ -515,7 +515,7 @@ func (d *Decoder) valueFromToml(mtype reflect.Type, tval interface{}) (reflect.V
 			if !val.Type().ConvertibleTo(mtype) {
 				return reflect.ValueOf(nil), fmt.Errorf("Can't convert %v(%T) to %v", tval, tval, mtype.String())
 			}
-			if reflect.Indirect(reflect.New(mtype)).OverflowInt(val.Int()) {
+			if reflect.Indirect(reflect.New(mtype)).OverflowInt(val.Convert(mtype).Int()) {
 				return reflect.ValueOf(nil), fmt.Errorf("%v(%T) would overflow %v", tval, tval, mtype.String())
 			}
 
@@ -525,10 +525,11 @@ func (d *Decoder) valueFromToml(mtype reflect.Type, tval interface{}) (reflect.V
 			if !val.Type().ConvertibleTo(mtype) {
 				return reflect.ValueOf(nil), fmt.Errorf("Can't convert %v(%T) to %v", tval, tval, mtype.String())
 			}
-			if val.Int() < 0 {
+
+			if val.Convert(reflect.TypeOf(int(1))).Int() < 0 {
 				return reflect.ValueOf(nil), fmt.Errorf("%v(%T) is negative so does not fit in %v", tval, tval, mtype.String())
 			}
-			if reflect.Indirect(reflect.New(mtype)).OverflowUint(uint64(val.Int())) {
+			if reflect.Indirect(reflect.New(mtype)).OverflowUint(uint64(val.Convert(mtype).Uint())) {
 				return reflect.ValueOf(nil), fmt.Errorf("%v(%T) would overflow %v", tval, tval, mtype.String())
 			}
 
@@ -538,7 +539,7 @@ func (d *Decoder) valueFromToml(mtype reflect.Type, tval interface{}) (reflect.V
 			if !val.Type().ConvertibleTo(mtype) {
 				return reflect.ValueOf(nil), fmt.Errorf("Can't convert %v(%T) to %v", tval, tval, mtype.String())
 			}
-			if reflect.Indirect(reflect.New(mtype)).OverflowFloat(val.Float()) {
+			if reflect.Indirect(reflect.New(mtype)).OverflowFloat(val.Convert(mtype).Float()) {
 				return reflect.ValueOf(nil), fmt.Errorf("%v(%T) would overflow %v", tval, tval, mtype.String())
 			}