diff --git a/zerostoragecaptcha.cpp b/zerostoragecaptcha.cpp
index 93f8dca..6b34067 100644
--- a/zerostoragecaptcha.cpp
+++ b/zerostoragecaptcha.cpp
@@ -126,10 +126,10 @@ void ZeroStorageCaptcha::updateCaptcha()
         painter.setPen(QPen(Qt::black, m_lineWidth));
         for (int i = 0; i < m_lineCount; i++)
         {
-            int x1 = (static_cast<qreal>(qrand()) / RAND_MAX) * m_captchaImage.width();
-            int y1 = (static_cast<qreal>(qrand()) / RAND_MAX) * m_captchaImage.height();
-            int x2 = (static_cast<qreal>(qrand()) / RAND_MAX) * m_captchaImage.width();
-            int y2 = (static_cast<qreal>(qrand()) / RAND_MAX) * m_captchaImage.height();
+            int x1 = static_cast<int>((static_cast<qreal>(qrand()) / RAND_MAX) * m_captchaImage.width());
+            int y1 = static_cast<int>((static_cast<qreal>(qrand()) / RAND_MAX) * m_captchaImage.height());
+            int x2 = static_cast<int>((static_cast<qreal>(qrand()) / RAND_MAX) * m_captchaImage.width());
+            int y2 = static_cast<int>((static_cast<qreal>(qrand()) / RAND_MAX) * m_captchaImage.height());
             painter.drawLine(x1, y1, x2, y2);
         }
         painter.setPen(Qt::NoPen);
diff --git a/zerostoragecaptchacrypto.cpp b/zerostoragecaptchacrypto.cpp
index 4c8f687..8e73ec0 100644
--- a/zerostoragecaptchacrypto.cpp
+++ b/zerostoragecaptchacrypto.cpp
@@ -60,12 +60,12 @@ QString KeyHolder::captchaSecretLine(const QString &captchaAnswer, bool prevTime
                                                           (prevTimeToken ? TimeToken::prevToken() : TimeToken::currentToken()) );
 
     uint8_t signature[SIGSIZE];
-    sign(reinterpret_cast<const uint8_t *>(hashedAnswer.toStdString().c_str()), hashedAnswer.size(), signature, m_key);
+    sign(reinterpret_cast<const uint8_t *>(hashedAnswer.toStdString().c_str()), static_cast<size_t>(hashedAnswer.size()), signature, m_key);
 
     QByteArray rawResultArray;
     for(int i = 0; i < SIGSIZE; ++i)
     {
-        rawResultArray += signature[i];
+        rawResultArray += static_cast<char>(signature[i]);
     }
 
     return compact(rawResultArray.toBase64(QByteArray::Base64Option::Base64UrlEncoding));