diff --git a/service/imaging/processor_default.go b/service/imaging/processor_default.go
index 2f5f9085b..addef26b1 100644
--- a/service/imaging/processor_default.go
+++ b/service/imaging/processor_default.go
@@ -87,7 +87,7 @@ func (p *defaultProcessor) FitAnimationGIF(srcFile io.Reader, width, height int)
 	}
 	// 画像が十分小さければスキップ
 	if srcWidth <= width && srcHeight <= height {
-		return imaging2.GifToBytesReader(src), nil
+		return imaging2.GifToBytesReader(src)
 	}
 
 	// 元の比率を保つよう調整
@@ -117,7 +117,7 @@ func (p *defaultProcessor) FitAnimationGIF(srcFile io.Reader, width, height int)
 		dst.Image = append(dst.Image, d)
 	}
 
-	return imaging2.GifToBytesReader(src), nil
+	return imaging2.GifToBytesReader(src)
 }
 
 func (p *defaultProcessor) WaveformMp3(src io.ReadSeeker, width, height int) (r io.Reader, err error) {
diff --git a/utils/imaging/gif.go b/utils/imaging/gif.go
index aa8575a51..d11b3f7a1 100644
--- a/utils/imaging/gif.go
+++ b/utils/imaging/gif.go
@@ -6,10 +6,10 @@ import (
 )
 
 // GifToBytesReader GIF画像を*bytes.Readerに書き出します
-func GifToBytesReader(src *gif.GIF) *bytes.Reader {
+func GifToBytesReader(src *gif.GIF) (*bytes.Reader, error) {
 	buf := new(bytes.Buffer)
 	if err := gif.EncodeAll(buf, src); err != nil {
-		panic(err)
+		return nil, err
 	}
-	return bytes.NewReader(buf.Bytes())
+	return bytes.NewReader(buf.Bytes()), nil
 }