diff --git a/src/Writer/CsvWriter.php b/src/Writer/CsvWriter.php
index d97023f7..d0c72496 100644
--- a/src/Writer/CsvWriter.php
+++ b/src/Writer/CsvWriter.php
@@ -138,10 +138,12 @@ public function write(array $data): void
         }
 
         // prevent csv injection
-        $patterns = ['/^=/', '/^\+/', '/^-/', '/^@/'];
-        $replace = ['!=', '!+', '!-', '!@'];
         foreach ($data as $key => $value) {
-            $data[$key] = preg_replace($patterns, $replace, $value);
+            $data[$key] = preg_replace(
+                ['/^=/', '/^\+/', '/^-/', '/^@/'],
+                ['\'=', '\'+', '\'-', '\'@'],
+                $value
+            );
         }
 
         $result = @fputcsv($this->file, $data, $this->delimiter, $this->enclosure, $this->escape);
diff --git a/src/Writer/XlsWriter.php b/src/Writer/XlsWriter.php
index 43ad5a2c..4a0ab464 100644
--- a/src/Writer/XlsWriter.php
+++ b/src/Writer/XlsWriter.php
@@ -79,10 +79,12 @@ public function write(array $data): void
 
         fwrite($this->file, '<tr>');
         // prevent xls injection
-        $patterns = ['/^=/', '/^\+/', '/^-/', '/^@/'];
-        $replace = ['!=', '!+', '!-', '!@'];
         foreach ($data as $value) {
-            fwrite($this->file, sprintf('<td>%s</td>', preg_replace($patterns, $replace, $value)));
+            fwrite($this->file, sprintf('<td>%s</td>', preg_replace(
+                ['/^=/', '/^\+/', '/^-/', '/^@/'],
+                ['\'=', '\'+', '\'-', '\'@'],
+                $value
+            )));
         }
         fwrite($this->file, '</tr>');