diff --git a/src/test/regress/pg_regress.c b/src/test/regress/pg_regress.c
index b4045abf21..3a39472108 100644
--- a/src/test/regress/pg_regress.c
+++ b/src/test/regress/pg_regress.c
@@ -861,6 +861,14 @@ initialize_environment(void)
 		if (user != NULL)
 			doputenv("PGUSER", user);
 
+		/*
+		 * However, we *don't* honor PGDATABASE, since we certainly don't wish
+		 * to connect to whatever database the user might like as default.
+		 * (Most tests override PGDATABASE anyway, but there are some ECPG
+		 * test cases that don't.)
+		 */
+		unsetenv("PGDATABASE");
+
 		/*
 		 * Report what we're connecting to
 		 */