diff --git a/plugins/openoffice/openoffice-write.c b/plugins/openoffice/openoffice-write.c
index 78c5989..a165591 100644
--- a/plugins/openoffice/openoffice-write.c
+++ b/plugins/openoffice/openoffice-write.c
@@ -2371,6 +2371,13 @@ odf_write_cell (GnmOOExport *state, GnmCell *cell, GnmRange const *merge_range,
 							OFFICE "value-type", "string");
 			break;
 		case VALUE_ERROR:
+			if (NULL == cell->base.texpr) {
+				char *eq_formula = g_strdup_printf ("of:=%s", value_peek_string (cell->value));
+				gsf_xml_out_add_cstr (state->xml,
+						      TABLE "formula",
+						      eq_formula);
+				g_free (eq_formula);
+			}
 			gsf_xml_out_add_cstr_unchecked (state->xml,
 							OFFICE "value-type", "string");
 			gsf_xml_out_add_cstr (state->xml,
