diff --git a/trezorlib/qt/pinmatrix.py b/trezorlib/qt/pinmatrix.py
index ce2a7c6958..768f6b59a3 100644
--- a/trezorlib/qt/pinmatrix.py
+++ b/trezorlib/qt/pinmatrix.py
@@ -1,9 +1,17 @@
 from __future__ import print_function
 import sys
 import math
-from PyQt4.QtGui import (QPushButton, QLineEdit, QSizePolicy, QRegExpValidator, QLabel,
-                         QApplication, QWidget, QGridLayout, QVBoxLayout, QHBoxLayout)
-from PyQt4.QtCore import QObject, SIGNAL, QRegExp, Qt
+
+try:
+    from PyQt4.QtGui import (QPushButton, QLineEdit, QSizePolicy, QRegExpValidator, QLabel,
+                             QApplication, QWidget, QGridLayout, QVBoxLayout, QHBoxLayout)
+    from PyQt4.QtCore import QObject, SIGNAL, QRegExp, Qt, QT_VERSION_STR
+except:
+    from PyQt5.QtWidgets import (QPushButton, QLineEdit, QSizePolicy, QLabel,
+                                 QApplication, QWidget, QGridLayout, QVBoxLayout, QHBoxLayout)
+    from PyQt5.QtGui import QRegExpValidator
+    from PyQt5.QtCore import QRegExp, Qt
+    from PyQt5.Qt import QT_VERSION_STR
 
 class PinButton(QPushButton):
     def __init__(self, password, encoded_value):
@@ -11,7 +19,12 @@ class PinButton(QPushButton):
         self.password = password
         self.encoded_value = encoded_value
 
-        QObject.connect(self, SIGNAL('clicked()'), self._pressed)
+        if QT_VERSION_STR >= '5':
+            self.clicked.connect(self._pressed)
+        elif QT_VERSION_STR >= '4':
+            QObject.connect(self, SIGNAL('clicked()'), self._pressed)
+        else:
+            raise Exception('Unsupported Qt version')
 
     def _pressed(self):
         self.password.setText(self.password.text() + str(self.encoded_value))
@@ -31,7 +44,13 @@ class PinMatrixWidget(QWidget):
         self.password = QLineEdit()
         self.password.setValidator(QRegExpValidator(QRegExp('[1-9]+'), None))
         self.password.setEchoMode(QLineEdit.Password)
-        QObject.connect(self.password, SIGNAL('textChanged(QString)'), self._password_changed)
+
+        if QT_VERSION_STR >= '5':
+            self.password.textChanged.connect(self._password_changed)
+        elif QT_VERSION_STR >= '4':
+            QObject.connect(self.password, SIGNAL('textChanged(QString)'), self._password_changed)
+        else:
+            raise Exception('Unsupported Qt version')
 
         self.strength = QLabel()
         self.strength.setMinimumWidth(75)
@@ -86,7 +105,7 @@ if __name__ == '__main__':
     '''
         Demo application showing PinMatrix widget in action
     '''
-    a = QApplication(sys.argv)
+    app = QApplication(sys.argv)
 
     matrix = PinMatrixWidget()
 
@@ -96,7 +115,12 @@ if __name__ == '__main__':
         sys.exit()
 
     ok = QPushButton('OK')
-    QObject.connect(ok, SIGNAL('clicked()'), clicked)
+    if QT_VERSION_STR >= '5':
+        ok.clicked.connect(clicked)
+    elif QT_VERSION_STR >= '4':
+        QObject.connect(ok, SIGNAL('clicked()'), clicked)
+    else:
+        raise Exception('Unsupported Qt version')
 
     vbox = QVBoxLayout()
     vbox.addWidget(matrix)
@@ -107,4 +131,4 @@ if __name__ == '__main__':
     w.move(100, 100)
     w.show()
 
-    a.exec_()
+    app.exec_()