diff --git a/pkg/dal/exec_join_left_test.go b/pkg/dal/exec_join_left_test.go
index 235ef92f4..e944f441e 100644
--- a/pkg/dal/exec_join_left_test.go
+++ b/pkg/dal/exec_join_left_test.go
@@ -1392,3 +1392,123 @@ func TestStepJoin_paging(t *testing.T) {
 		})
 	}
 }
+
+func TestStepJoin_multiValueFields(t *testing.T) {
+	basicLocalAttrs := []simpleAttribute{
+		{ident: "l_pk", t: TypeID{}},
+		{ident: "l_ref", t: TypeID{}},
+		{ident: "l_val", t: TypeText{}},
+	}
+	basicForeignAttrs := []simpleAttribute{
+		{ident: "f_pk", t: TypeID{}},
+		{ident: "f_fk", t: TypeRef{}},
+		{ident: "f_val", t: TypeText{}},
+	}
+
+	basicAttrs := append(basicLocalAttrs, basicForeignAttrs...)
+
+	tcc := []struct {
+		name string
+
+		outAttributes   []simpleAttribute
+		leftAttributes  []simpleAttribute
+		rightAttributes []simpleAttribute
+		joinPred        JoinPredicate
+
+		lIn []*Row
+		fIn []*Row
+		out []*Row
+	}{
+		{
+			name: "multiple left keys",
+
+			outAttributes:   basicAttrs,
+			leftAttributes:  basicLocalAttrs,
+			rightAttributes: basicForeignAttrs,
+			joinPred:        JoinPredicate{Left: "l_ref", Right: "f_fk"},
+
+			lIn: []*Row{
+				(&Row{}).
+					WithValue("l_pk", 0, 1).
+					WithValue("l_ref", 0, 1).
+					WithValue("l_ref", 1, 2).
+					WithValue("l_val", 0, "l1 v1"),
+			},
+			fIn: []*Row{
+				(&Row{}).
+					WithValue("f_pk", 0, 1).
+					WithValue("f_fk", 0, 1).
+					WithValue("f_val", 0, "f1 v1"),
+
+				(&Row{}).
+					WithValue("f_pk", 0, 2).
+					WithValue("f_fk", 0, 2).
+					WithValue("f_val", 0, "f1 v2"),
+			},
+
+			out: []*Row{
+				(&Row{}).
+					WithValue("l_pk", 0, 1).
+					WithValue("l_ref", 0, 1).
+					WithValue("l_ref", 1, 2).
+					WithValue("l_val", 0, "l1 v1").
+					// ...
+					WithValue("f_pk", 0, 1).
+					WithValue("f_fk", 0, 1).
+					WithValue("f_val", 0, "f1 v1"),
+
+				(&Row{}).
+					WithValue("l_pk", 0, 1).
+					WithValue("l_ref", 0, 1).
+					WithValue("l_ref", 1, 2).
+					WithValue("l_val", 0, "l1 v1").
+					// ...
+					WithValue("f_pk", 0, 2).
+					WithValue("f_fk", 0, 2).
+					WithValue("f_val", 0, "f1 v2"),
+			},
+		},
+	}
+
+	ctx := context.Background()
+	for _, tc := range tcc {
+		t.Run(tc.name, func(t *testing.T) {
+			l := InMemoryBuffer()
+			for _, r := range tc.lIn {
+				require.NoError(t, l.Add(ctx, r))
+			}
+
+			f := InMemoryBuffer()
+			for _, r := range tc.fIn {
+				require.NoError(t, f.Add(ctx, r))
+			}
+
+			def := Join{
+				Ident:           "foo",
+				On:              tc.joinPred,
+				OutAttributes:   saToMapping(tc.outAttributes...),
+				LeftAttributes:  saToMapping(tc.leftAttributes...),
+				RightAttributes: saToMapping(tc.rightAttributes...),
+				Filter:          filter.Generic(filter.WithOrderBy(filter.SortExprSet{{Column: "l_pk"}, {Column: "f_pk"}})),
+
+				plan: joinPlan{},
+			}
+
+			xs, err := def.iterator(ctx, l, f)
+			require.NoError(t, err)
+
+			i := 0
+			for xs.Next(ctx) {
+				require.NoError(t, xs.Err())
+				out := &Row{}
+				require.NoError(t, xs.Err())
+				require.NoError(t, xs.Scan(out))
+
+				require.Equal(t, tc.out[i], out)
+
+				i++
+			}
+			require.Equal(t, len(tc.out), i)
+		})
+	}
+}