diff --git a/src/backend/parser/parse_expr.c b/src/backend/parser/parse_expr.c
index 97f535a2f0..2fd233bf18 100644
--- a/src/backend/parser/parse_expr.c
+++ b/src/backend/parser/parse_expr.c
@@ -2376,6 +2376,15 @@ transformMinMaxExpr(ParseState *pstate, MinMaxExpr *m)
 static Node *
 transformSQLValueFunction(ParseState *pstate, SQLValueFunction *svf)
 {
+	/*
+	 * All SQL value functions are stable so we reject them in check
+	 * constraint expressions.
+	 */
+	if (pstate->p_expr_kind == EXPR_KIND_CHECK_CONSTRAINT)
+		ereport(ERROR,
+				(errcode(ERRCODE_INVALID_OBJECT_DEFINITION),
+				 errmsg("mutable functions are not allowed in check constraints")));
+
 	/*
 	 * All we need to do is insert the correct result type and (where needed)
 	 * validate the typmod, so we just modify the node in-place.
diff --git a/src/backend/parser/parse_func.c b/src/backend/parser/parse_func.c
index 2a44b434a5..6ea2f0326d 100644
--- a/src/backend/parser/parse_func.c
+++ b/src/backend/parser/parse_func.c
@@ -271,6 +271,13 @@ ParseFuncOrColumn(ParseState *pstate, List *funcname, List *fargs,
 							   &nvargs, &vatype,
 							   &declared_arg_types, &argdefaults);
 
+	/* mutable functions are not allowed in constraint expressions */
+	if (pstate->p_expr_kind == EXPR_KIND_CHECK_CONSTRAINT &&
+		func_volatile(funcid) != PROVOLATILE_IMMUTABLE)
+		ereport(ERROR,
+				(errcode(ERRCODE_INVALID_OBJECT_DEFINITION),
+				 errmsg("mutable functions are not allowed in constraint expression")));
+
 	cancel_parser_errposition_callback(&pcbstate);
 
 	/*