diff --git a/app/Services/CheckinCsvImporter.php b/app/Services/CheckinCsvImporter.php
index c424dd1..834ca5f 100644
--- a/app/Services/CheckinCsvImporter.php
+++ b/app/Services/CheckinCsvImporter.php
@@ -178,6 +178,9 @@ class CheckinCsvImporter
             if (strpos($tag, "\n") !== false) {
                 throw new CsvImportException("{$line} 行 : {$column}に改行を含めることはできません。");
             }
+            if (strpos($tag, ' ') !== false) {
+                throw new CsvImportException("{$line} 行 : {$column}にスペースを含めることはできません。");
+            }
 
             $tags[] = Tag::firstOrCreate(['name' => $tag]);
             if (count($tags) >= 32) {
diff --git a/tests/Unit/Services/CheckinCsvImporterTest.php b/tests/Unit/Services/CheckinCsvImporterTest.php
index 07c9be4..e3e9be3 100644
--- a/tests/Unit/Services/CheckinCsvImporterTest.php
+++ b/tests/Unit/Services/CheckinCsvImporterTest.php
@@ -240,6 +240,16 @@ class CheckinCsvImporterTest extends TestCase
         $importer->execute();
     }
 
+    public function testTagCantAcceptWhitespaceUTF8()
+    {
+        $user = factory(User::class)->create();
+        $this->expectException(CsvImportException::class);
+        $this->expectExceptionMessage('2 行 : タグ1にスペースを含めることはできません。');
+
+        $importer = new CheckinCsvImporter($user, __DIR__ . '/../../fixture/Csv/tag-whitespace.utf8.csv');
+        $importer->execute();
+    }
+
     public function testTagCanAccept32ColumnsUTF8()
     {
         $user = factory(User::class)->create();
diff --git a/tests/fixture/Csv/tag-whitespace.utf8.csv b/tests/fixture/Csv/tag-whitespace.utf8.csv
new file mode 100644
index 0000000..2e5f0ce
--- /dev/null
+++ b/tests/fixture/Csv/tag-whitespace.utf8.csv
@@ -0,0 +1,2 @@
+日時,タグ1
+2020/01/23 06:01,"空白を含む タグ"