diff --git a/src/tests/add-ons/kernel/file_systems/bfs/bfs_shell/Jamfile b/src/tests/add-ons/kernel/file_systems/bfs/bfs_shell/Jamfile
index ddb32a2f29..4dceaa3d45 100644
--- a/src/tests/add-ons/kernel/file_systems/bfs/bfs_shell/Jamfile
+++ b/src/tests/add-ons/kernel/file_systems/bfs/bfs_shell/Jamfile
@@ -24,7 +24,8 @@ C++FLAGS = [ Filter $(C++FLAGS) : -nostdinc ] ;
 
 Objects [ FGristFiles additional_commands.c ] ;
 
-ObjectsDefines [ FGristFiles additional_commands.c ] : _NO_INLINE_ASM ;
+ObjectsDefines [ FGristFiles additional_commands.c ]
+	: _NO_INLINE_ASM _GNU_SOURCE ;
 
 # Reset CCFLAGS and C++FLAGS to original values.
 CCFLAGS = $(oldCCFLAGS) ;