diff --git a/var/spack/repos/builtin/packages/libiconv/package.py b/var/spack/repos/builtin/packages/libiconv/package.py
index 1e3d29a4dfdce8df70bda159370faadc07551afe..bf0ee46b2d3b3dd0f2e392c9b19b6eeed75c93b9 100644
--- a/var/spack/repos/builtin/packages/libiconv/package.py
+++ b/var/spack/repos/builtin/packages/libiconv/package.py
@@ -40,6 +40,8 @@ class Libiconv(AutotoolsPackage):
     # of C11 any more and thus might not exist.
     patch('gets.patch', when='@1.14')
 
+    conflicts('@1.14', when='%gcc@5:')
+
     def configure_args(self):
         args = ['--enable-extra-encodings']