diff --git a/src/mcedit2/rendering/textureatlas.py b/src/mcedit2/rendering/textureatlas.py
index 920f34b..35dc61b 100644
--- a/src/mcedit2/rendering/textureatlas.py
+++ b/src/mcedit2/rendering/textureatlas.py
@@ -331,6 +331,9 @@ def getGLMaximumTextureSize():
     return _maxSize
 
 def _getMaxSize():
+    if QtOpenGL.QGLContext.currentContext() is None:
+        pbuf = QtOpenGL.QGLPixelBuffer(100, 100)
+        pbuf.makeCurrent()
     size = 16384
     while size > 0:
         size /= 2