diff --git a/src/backend/commands/copy.c b/src/backend/commands/copy.c
index 70ee7e5..540da91 100644
--- a/src/backend/commands/copy.c
+++ b/src/backend/commands/copy.c
@@ -1457,6 +1457,26 @@ BeginCopy(bool is_from,
 		}
 	}
 
+	/*
+	 * Check if both force_null and force_not_null are used on the same
+	 * columns.
+	 */
+	if (cstate->force_null && cstate->force_notnull)
+	{
+		int i;
+
+		for (i = 0; i < num_phys_attrs; i++)
+		{
+			if (cstate->force_notnull_flags[i] &&
+				cstate->force_null_flags[i])
+				ereport(ERROR,
+						(errcode(ERRCODE_SYNTAX_ERROR),
+						 errmsg("conflicting or redundant options"),
+						 errhint("\"force_not_null\" and \"force_null\" specified for the same column \"%s\"",
+								 NameStr(tupDesc->attrs[i]->attname))));
+		}
+	}
+
 	/* Use client encoding when ENCODING option is not specified. */
 	if (cstate->file_encoding < 0)
 		cstate->file_encoding = pg_get_client_encoding();
diff --git a/src/test/regress/expected/copy2.out b/src/test/regress/expected/copy2.out
index 76dea28..5341b09 100644
--- a/src/test/regress/expected/copy2.out
+++ b/src/test/regress/expected/copy2.out
@@ -418,6 +418,12 @@ ERROR:  null value in column "b" violates not-null constraint
 DETAIL:  Failing row contains (3, null, , null, null).
 CONTEXT:  COPY forcetest, line 1: "3,,"""
 ROLLBACK;
+-- FORCE_NULL and FORCE_NOT_NULL cannot be used on the same column
+BEGIN;
+COPY forcetest (a) FROM STDIN WITH (FORMAT csv, FORCE_NULL(a), FORCE_NOT_NULL(a));
+ERROR:  conflicting or redundant options
+HINT:  "force_not_null" and "force_null" specified for the same column "a"
+ROLLBACK;
 -- should fail with "not referenced by COPY" error
 BEGIN;
 COPY forcetest (d, e) FROM STDIN WITH (FORMAT csv, FORCE_NOT_NULL(b));
diff --git a/src/test/regress/sql/copy2.sql b/src/test/regress/sql/copy2.sql
index e2be21f..91dc902 100644
--- a/src/test/regress/sql/copy2.sql
+++ b/src/test/regress/sql/copy2.sql
@@ -299,6 +299,10 @@ COPY forcetest (a, b, c) FROM STDIN WITH (FORMAT csv, FORCE_NULL(b), FORCE_NOT_N
 3,,""
 \.
 ROLLBACK;
+-- FORCE_NULL and FORCE_NOT_NULL cannot be used on the same column
+BEGIN;
+COPY forcetest (a) FROM STDIN WITH (FORMAT csv, FORCE_NULL(a), FORCE_NOT_NULL(a));
+ROLLBACK;
 -- should fail with "not referenced by COPY" error
 BEGIN;
 COPY forcetest (d, e) FROM STDIN WITH (FORMAT csv, FORCE_NOT_NULL(b));