diff --git a/toolchain/external-toolchain/ext-tool.mk b/toolchain/external-toolchain/ext-tool.mk
index e858edb8c2..8daae15aec 100644
--- a/toolchain/external-toolchain/ext-tool.mk
+++ b/toolchain/external-toolchain/ext-tool.mk
@@ -264,6 +264,9 @@ endif
 
 ifneq ($(BR2_PTHREADS_NONE),y)
 EXTERNAL_LIBS+=libpthread.so
+ifeq ($(BR2_PACKAGE_GDB_SERVER),y)
+EXTERNAL_LIBS+=libthread_db.so
+endif # gdbserver
 endif # ! no threads
 
 # SYSROOT_DIR selection. We first try the -print-sysroot option,