diff --git a/postfix.changes b/postfix.changes
index 056da22..255d63e 100644
--- a/postfix.changes
+++ b/postfix.changes
@@ -1,3 +1,10 @@
+-------------------------------------------------------------------
+Fri Mar  1 16:23:13 UTC 2019 - Reinhard Max <max@suse.com>
+
+- PostrgeSQL's pg_config is meant for linking server extensions,
+  use libpq's pkg-config instead, if available.
+  This is needed to fix build with PostgreSQL 11.
+
 -------------------------------------------------------------------
 Thu Feb  7 18:22:14 UTC 2019 - chris@computersalat.de
 
diff --git a/postfix.spec b/postfix.spec
index b6504f6..6721ed0 100644
--- a/postfix.spec
+++ b/postfix.spec
@@ -207,11 +207,17 @@ else
   export AUXLIBS="$AUXLIBS -lsasl2"
 fi
 #
+set -x
 export CCARGS="${CCARGS} -DHAS_MYSQL $(mysql_config --cflags)"
 export AUXLIBS_MYSQL="$(mysql_config --libs)"
 #
-export CCARGS="${CCARGS} -DHAS_PGSQL -I$(pg_config --includedir)"
-export AUXLIBS_PGSQL="-lpq"
+if pkg-config libpq ; then
+  export CCARGS="${CCARGS} -DHAS_PGSQL $(pkg-config libpq --cflags)"
+  export AUXLIBS_PGSQL="$(pkg-config libpq --libs)"
+else
+  export CCARGS="${CCARGS} -DHAS_PGSQL -I$(pg_config --includedir)"
+  export AUXLIBS_PGSQL="-lpq"
+fi
 #
 %if %{with lmdb}
 export CCARGS="${CCARGS} -DHAS_LMDB -I/usr/local/include" \