diff --git a/nmigen/vendor/board/tinyfpga_bx.py b/nmigen/vendor/board/tinyfpga_bx.py
index 2c82146..9afb1dc 100644
--- a/nmigen/vendor/board/tinyfpga_bx.py
+++ b/nmigen/vendor/board/tinyfpga_bx.py
@@ -13,7 +13,7 @@ class TinyFPGABXPlatform(TinyProgrammerMixin, LatticeICE40Platform):
     ]
     resources  = [
         Resource("clk16", 0, Pins("B2", dir="i"),
-                 extras={"GLOBAL": 1, "IO_STANDARD": "SB_LVCMOS33"}),
+                 extras={"GLOBAL": "1", "IO_STANDARD": "SB_LVCMOS33"}),
 
         Resource("user_led", 0, Pins("B3", dir="o"), extras={"IO_STANDARD": "SB_LVCMOS33"}),