diff --git a/cross_arm.txt b/cross_arm.txt
index fd8a0153..41717a79 100644
--- a/cross_arm.txt
+++ b/cross_arm.txt
@@ -14,6 +14,7 @@ openocd = '/usr/local/bin/openocd'
 
 [properties]
 c_args      = [
+               '-fcommon',
                '-mcpu=cortex-m4',           # Cortex-M4 CPU
                '-mthumb',                   # ARM Thumb2 ISA
                '-mfloat-abi=hard',          # Hard floating point support