diff --git a/targets/rp2040/BUILD.gn b/targets/rp2040/BUILD.gn
index 9f0bbdb..d256414 100644
--- a/targets/rp2040/BUILD.gn
+++ b/targets/rp2040/BUILD.gn
@@ -43,7 +43,6 @@
   ]
   _toolchain_base = pw_toolchain_arm_gcc.cortex_m0plus_size_optimized
   forward_variables_from(_toolchain_base, "*", _excluded_members)
-  final_binary_extension = ".elf"
 
   # For now, no Pigweed configurations set up.
   defaults = {