diff --git a/dev/buildbot/master/master.cfg b/dev/buildbot/master/master.cfg
index 0b34e888..a43c897b 100644
--- a/dev/buildbot/master/master.cfg
+++ b/dev/buildbot/master/master.cfg
@@ -1043,7 +1043,7 @@ for platform in ['OSX', 'linux', 'windows']:
         if wrapper == '64BIT_STATIC_LIBRARY':
             cmake_args += ['-DCOOLPROP_STATIC_LIBRARY=ON','-DCOOLPROP_EXTERNC_LIBRARY=ON']
         if wrapper == 'R':
-            if plaform.startwith('windows'):
+            if platform.startwith('windows'):
                 cmake_args += ['-DR_BIN="C:/Program Files/R/R-3.2.1/bin/x64"']
             elif platform == 'OSX':
                 cmake_args += ['-DR_BIN="/usr/bin/local"']