diff --git a/toolchain/gdb/Config.in b/toolchain/gdb/Config.in
index ca0c821..66f1b42 100644
--- a/toolchain/gdb/Config.in
+++ b/toolchain/gdb/Config.in
@@ -20,7 +20,14 @@ comment "Gdb debugger for the target needs WCHAR support in toolchain"
 
 config BR2_PACKAGE_GDB_SERVER
 	bool "Build gdb server for the Target"
-	depends on !BR2_TOOLCHAIN_EXTERNAL
+	# In order to guarantee the compatibility between the cross
+	# gdb and the gdbserver, we expect external toolchains to
+	# provide both cross gcc and gdbserver. Unfortunately,
+	# external toolchains provided by Analog Devices for Blackfin
+	# do not come with a gdbserver, so we exceptionnally allow the
+	# building on gdbserver even with external toolchains in the
+	# Blackfin case.
+	depends on !BR2_TOOLCHAIN_EXTERNAL || BR2_bfin
 	help
 	    Build the gdbserver stub to run on the target.
 	    A full gdb is needed to debug the progam.