diff --git a/src/test/regress/regress.c b/src/test/regress/regress.c
index d5aafdf370c..90bb2a7e881 100644
--- a/src/test/regress/regress.c
+++ b/src/test/regress/regress.c
@@ -1335,9 +1335,15 @@ test_translation(PG_FUNCTION_ARGS)
 		 * Apparently the customary workaround is for users to set the
 		 * LANGUAGE environment variable to provide a mapping.  Do so here to
 		 * ensure that the nls.sql regression test will work.
+		 *
+		 * With glibc and perhaps other implementations, LANGUAGE overrides
+		 * LC_MESSAGES, which we don't want either; so let's unset it if we're
+		 * not on Solaris.
 		 */
 #if defined(__sun__)
 		setenv("LANGUAGE", "es_ES.UTF-8:es", 1);
+#else
+		unsetenv("LANGUAGE");
 #endif
 		pg_bindtextdomain(TEXTDOMAIN);
 		inited = true;