--- a/dev-libs/libxml2/libxml2-2.9.7.ebuild	2018-01-13 12:42:37.000000000 +0100
+++ a/dev-libs/libxml2/libxml2-2.9.7.ebuild	2018-01-19 15:02:23.691845200 +0100
@@ -157,6 +157,12 @@ 
 			exampledir="${EPREFIX}"/usr/share/doc/${PF}/python/examples \
 			install
 		python_foreach_impl python_optimize
+
+		# On cygwin the module is named cygxml2mod.dll. This is generally
+		# correct, but python can only handle modules with lib prefix.
+		if use elibc_Cygwin; then
+			python_foreach_impl libxml2_py_cygwin_rename
+		fi
 	fi
 }
 
@@ -206,3 +212,8 @@ 
 	emake "$@"
 	popd > /dev/null
 }
+
+libxml2_py_cygwin_rename() {
+	mv "${D}$(python_get_sitedir)"/{cyg,lib}xml2mod.dll \
+				|| die "$EPYTHON cygxml2mod.dll rename failed"
+}