diff --git a/dev-lang/polyml/files/polyml-5.6-configure.patch b/dev-lang/polyml/files/polyml-5.6-configure.patch
new file mode 100644
index 0000000000000..ba3b6bbbd5acf
--- /dev/null
+++ b/dev-lang/polyml/files/polyml-5.6-configure.patch
@@ -0,0 +1,11 @@
+--- a/configure.ac	2019-04-05 10:27:19.026197625 +0200
++++ b/configure.ac	2019-04-05 10:28:10.187291374 +0200
+@@ -133,7 +133,7 @@
+ # Solaris needs -lsocket, -lnsl and -lrt
+ AC_SEARCH_LIBS([gethostbyname], [nsl])
+ AC_SEARCH_LIBS([getsockopt], [socket])
+-AC_SEARCH_LIBS([sem_wait], [rt])
++AC_SEARCH_LIBS([sem_wait], [rt] [pthread])
+ 
+ # Check for X and Motif headers and libraries
+ AC_PATH_X
diff --git a/dev-lang/polyml/polyml-5.6.ebuild b/dev-lang/polyml/polyml-5.6.ebuild
index 6cdf4fdd6fb5d..1182c2d0766c7 100644
--- a/dev-lang/polyml/polyml-5.6.ebuild
+++ b/dev-lang/polyml/polyml-5.6.ebuild
@@ -1,4 +1,4 @@
-# Copyright 1999-2018 Gentoo Foundation
+# Copyright 1999-2019 Gentoo Authors
 # Distributed under the terms of the GNU General Public License v2
 
 EAPI="6"
@@ -20,6 +20,8 @@ RDEPEND="X? ( x11-libs/motif:0 )
 		virtual/libffi"
 DEPEND="${RDEPEND}"
 
+PATCHES=( "${FILESDIR}"/${P}-configure.patch )
+
 src_prepare() {
 	default
 	eautoreconf