diff --git a/Makefile.top b/Makefile.top
index 727f08bf49..66aaecf7bd 100644
--- a/Makefile.top
+++ b/Makefile.top
@@ -11,6 +11,13 @@ AM_CPPFLAGS =					\
 	-include $(top_builddir)/config.h	\
 	-I$(srcdir)/include
 
+AM_LDFLAGS =
+
+if HOST_MACOS
+AM_LDFLAGS +=					\
+	-Wl,-flat_namespace
+endif HOST_MACOS
+
 if HAVE_GSSAPI
 AM_CPPFLAGS +=					\
 	$(GSSAPI_CFLAGS)
diff --git a/configure.ac b/configure.ac
index 441e150447..97286bcd98 100644
--- a/configure.ac
+++ b/configure.ac
@@ -150,6 +150,10 @@ AX_CHECK_COMPILE_FLAG([-Werror -fno-delete-null-pointer-checks],
 AX_CHECK_COMPILE_FLAG([-fdiagnostics-show-option],
 		      [STD_CFLAGS="$STD_CFLAGS -fdiagnostics-show-option"])
 
+host_macos=no
+AS_CASE([$host],[*-darwin*],[host_macos=yes])
+AM_CONDITIONAL([HOST_MACOS], [test "$host_macos" = "yes"])
+
 #
 # Change defaults for developers if not explicity set.
 # Needs to be before the option is tested.
diff --git a/fuzz/Makefile.am b/fuzz/Makefile.am
index 4ba24e4029..bf5aa3eeb2 100644
--- a/fuzz/Makefile.am
+++ b/fuzz/Makefile.am
@@ -5,7 +5,7 @@ AM_CPPFLAGS +=				\
 	$(LIBDNS_CFLAGS)		\
 	-DFUZZDIR=\"$(abs_srcdir)\"
 
-AM_LDFLAGS =				\
+AM_LDFLAGS +=				\
 	$(FUZZ_LDFLAGS)
 
 LDADD =					\
diff --git a/lib/bind9/Makefile.am b/lib/bind9/Makefile.am
index 3501cef49c..6b7edf8c9a 100644
--- a/lib/bind9/Makefile.am
+++ b/lib/bind9/Makefile.am
@@ -27,6 +27,7 @@ libbind9_la_LIBADD =		\
 	$(LIBISCCFG_LIBS)
 
 libbind9_la_LDFLAGS =		\
+	$(AM_LDFLAGS)		\
 	$(libbind9_VERSION_INFO)
 
 EXTRA_DIST = api
diff --git a/lib/dns/Makefile.am b/lib/dns/Makefile.am
index 78a2752c90..73e6bc2f73 100644
--- a/lib/dns/Makefile.am
+++ b/lib/dns/Makefile.am
@@ -287,6 +287,7 @@ libdns_la_CPPFLAGS =		\
 	$(LIBLTDL_CFLAGS)
 
 libdns_la_LDFLAGS =		\
+	$(AM_LDFLAGS)		\
 	$(libdns_VERSION_INFO)
 
 libdns_la_LIBADD =		\
diff --git a/lib/irs/Makefile.am b/lib/irs/Makefile.am
index 75d514cbcb..f7b82b47bc 100644
--- a/lib/irs/Makefile.am
+++ b/lib/irs/Makefile.am
@@ -23,6 +23,7 @@ libirs_la_LIBADD =		\
 	$(LIBISCCFG_LIBS)
 
 libirs_la_LDFLAGS =		\
+	$(AM_LDFLAGS)		\
 	$(libirs_VERSION_INFO)
 
 
diff --git a/lib/isc/Makefile.am b/lib/isc/Makefile.am
index cde0947bde..2c84285b16 100644
--- a/lib/isc/Makefile.am
+++ b/lib/isc/Makefile.am
@@ -227,6 +227,7 @@ libisc_la_CPPFLAGS =		\
 	$(ZLIB_CFLAGS)
 
 libisc_la_LDFLAGS =		\
+	$(AM_LDFLAGS)		\
 	$(libisc_VERSION_INFO)
 
 libisc_la_LIBADD =		\
diff --git a/lib/isccc/Makefile.am b/lib/isccc/Makefile.am
index 477cc525fb..aca06f777f 100644
--- a/lib/isccc/Makefile.am
+++ b/lib/isccc/Makefile.am
@@ -35,6 +35,7 @@ libisccc_la_LIBADD =	\
 	$(LIBISC_LIBS)
 
 libisccc_la_LDFLAGS =		\
+	$(AM_LDFLAGS)		\
 	$(libisccc_VERSION_INFO)
 
 if HAVE_CMOCKA
diff --git a/lib/isccfg/Makefile.am b/lib/isccfg/Makefile.am
index ef0cd16fc8..eb4b7d53d9 100644
--- a/lib/isccfg/Makefile.am
+++ b/lib/isccfg/Makefile.am
@@ -32,6 +32,7 @@ libisccfg_la_LIBADD =	\
 	$(LIBDNS_LIBS)
 
 libisccfg_la_LDFLAGS =		\
+	$(AM_LDFLAGS)		\
 	$(libisccfg_VERSION_INFO)
 
 if HAVE_CMOCKA
diff --git a/lib/ns/Makefile.am b/lib/ns/Makefile.am
index b2f81ccf08..7f79af4292 100644
--- a/lib/ns/Makefile.am
+++ b/lib/ns/Makefile.am
@@ -51,6 +51,7 @@ libns_la_LIBADD =	\
 	$(LIBDNS_LIBS)
 
 libns_la_LDFLAGS =		\
+	$(AM_LDFLAGS)		\
 	$(libns_VERSION_INFO)
 
 if HAVE_CMOCKA