Index: configure.ac
==================================================================
--- configure.ac
+++ configure.ac
@@ -415,10 +415,12 @@
 case "$host_os" in
 	darwin*)
 		AC_SUBST(LDFLAGS_REEXPORT, ["-Wl,-reexport-lobjfw"])
 		AS_IF([test x"$objc_runtime" = x"Apple runtime"], [
 			AC_SUBST(REEXPORT_LIBOBJC, ["-Wl,-reexport-lobjc"])
+			AC_SUBST(WEAK_NSFOUNDATIONVERSIONNUMBER,
+				["-Wl,-U,_NSFoundationVersionNumber"])
 			LDFLAGS="$LDFLAGS -Wl,-U,_NSFoundationVersionNumber"
 		])
 
 		AS_IF([test x"$objc_runtime" = x"ObjFW runtime"], [
 			AS_IF([test x"$exception_type" = x"DWARF"], [

Index: extra.mk.in
==================================================================
--- extra.mk.in
+++ extra.mk.in
@@ -59,5 +59,6 @@
 USE_INCLUDES_ATOMIC = @USE_INCLUDES_ATOMIC@
 USE_SRCS_FILES = @USE_SRCS_FILES@
 USE_SRCS_PLUGINS = @USE_SRCS_PLUGINS@
 USE_SRCS_SOCKETS = @USE_SRCS_SOCKETS@
 USE_SRCS_THREADS = @USE_SRCS_THREADS@
+WEAK_NSFOUNDATIONVERSIONNUMBER = @WEAK_NSFOUNDATIONVERSIONNUMBER@

Index: utils/objfw-config.in
==================================================================
--- utils/objfw-config.in
+++ utils/objfw-config.in
@@ -27,11 +27,11 @@
 OBJCFLAGS="$OBJCFLAGS @NO_CONST_CFSTRINGS@ @BLOCKS_FLAGS@"
 LIB_CFLAGS="@LIB_CFLAGS@"
 LIB_LDFLAGS="@LIB_LDFLAGS@"
 LIB_PREFIX="@LIB_PREFIX@"
 LIB_SUFFIX="@LIB_SUFFIX@"
-LDFLAGS="@ALLOW_MULTIPLE_DEFINITION@"
+LDFLAGS="@ALLOW_MULTIPLE_DEFINITION@ @WEAK_NSFOUNDATIONVERSIONNUMBER@"
 LDFLAGS_REEXPORT="@LDFLAGS_REEXPORT@"
 LDFLAGS_RPATH="@LDFLAGS_RPATH@"
 LIBS="-L${libdir} -lobjfw @LIBS@"
 PLUGIN_CFLAGS="@PLUGIN_CFLAGS@"
 PLUGIN_LDFLAGS="@PLUGIN_LDFLAGS@"