Index: lib/libkvm/kvm.c
===================================================================
--- lib/libkvm/kvm.c
+++ lib/libkvm/kvm.c
@@ -64,7 +64,7 @@
 
 #include "kvm_private.h"
 
-SET_DECLARE(kvm_arch, struct kvm_arch);
+SET_DECLARE_WEAK(kvm_arch, struct kvm_arch);
 
 static char _kd_is_null[] = "";
 
Index: sys/dev/uart/uart_cpu_acpi.h
===================================================================
--- sys/dev/uart/uart_cpu_acpi.h
+++ sys/dev/uart/uart_cpu_acpi.h
@@ -62,7 +62,7 @@
  * If your UART driver implements uart_class and custom device layer,
  * then use UART_ACPI_CLASS for its declaration
  */
-SET_DECLARE(uart_acpi_class_set, struct acpi_uart_compat_data);
+SET_DECLARE_WEAK(uart_acpi_class_set, struct acpi_uart_compat_data);
 #define UART_ACPI_CLASS(data)				\
 	DATA_SET(uart_acpi_class_set, data)
 
Index: sys/dev/uart/uart_cpu_fdt.h
===================================================================
--- sys/dev/uart/uart_cpu_fdt.h
+++ sys/dev/uart/uart_cpu_fdt.h
@@ -46,7 +46,7 @@
  * If your UART driver implements uart_class and custom device layer,
  * then use UART_FDT_CLASS for its declaration
  */
-SET_DECLARE(uart_fdt_class_set, struct ofw_compat_data );
+SET_DECLARE_WEAK(uart_fdt_class_set, struct ofw_compat_data );
 #define UART_FDT_CLASS(data)				\
 	DATA_SET(uart_fdt_class_set, data)
 
Index: sys/kern/subr_compressor.c
===================================================================
--- sys/kern/subr_compressor.c
+++ sys/kern/subr_compressor.c
@@ -62,7 +62,7 @@
 	void *arg;
 };
 
-SET_DECLARE(compressors, struct compressor_methods);
+SET_DECLARE_WEAK(compressors, struct compressor_methods);
 
 #ifdef GZIO
 
Index: sys/sys/linker_set.h
===================================================================
--- sys/sys/linker_set.h
+++ sys/sys/linker_set.h
@@ -60,8 +60,6 @@
  */
 #ifdef __GNUCLIKE___SECTION
 #define __MAKE_SET_QV(set, sym, qv)			\
-	__GLOBL(__CONCAT(__start_set_,set));		\
-	__GLOBL(__CONCAT(__stop_set_,set));		\
 	static void const * qv				\
 	__set_##set##_sym_##sym __section("set_" #set)	\
 	__nosanitizeaddress				\
@@ -84,7 +82,12 @@
 /*
  * Initialize before referring to a given linker set.
  */
-#define SET_DECLARE(set, ptype)					\
+#define SET_DECLARE(set, ptype)				\
+	extern ptype *__CONCAT(__start_set_,set);	\
+	extern ptype *__CONCAT(__stop_set_,set)
+
+/* Like SET_DECLARE() but also marks the symbols weak to support empty sets. */
+#define SET_DECLARE_WEAK(set, ptype)				\
 	extern ptype __weak_symbol *__CONCAT(__start_set_,set);	\
 	extern ptype __weak_symbol *__CONCAT(__stop_set_,set)