Professors reveal their gender bias and hurt female science students when they write letters of recommendation describing them as “hard-working,” “kind,” or “conscientious,” one lecturer told Oxford physics students last month.

Athene Donald, a Cambridge experimental physics prof, recounted her Oxford lecture in a blog post republished by Times Higher Education. She claims that “gendered adjectives” in letters of recommendation are a “significant detriment to the woman’s progression even without a sexist intent.”

“Gendered adjectives,” which should supposedly be avoided, also include “dependable,” “warm,” and “diligent,” according to a University of Arizona guide that Donald references.

Not sure if a letter of recommendation is sexist? Well, Donald says, there’s a gender-bias calculator for that.

The calculator relies on a list of words from a 2007 paper accessible on the National Institutes of Health, which examined how “gendered stereotypes could bias how recommenders describe female compared to male applicants.”

Paste in a drafted letter of recommendation, and the calculator will highlight male-associated words, which are theoretically acceptable for use, and female-associated words, which should be avoided.

The gender-bias calculator tool captures not just gendered adjectives but also female-associated nouns, which apparently include “student,” “class,” “education,” and “work.” (In contrast, “question” and “publication” are all male-associated words, according to the calculator.)

Donald bemoans how the problem of gendered words in letters of recommendation “had not yet received a great deal of attention” until recently.

And it’s problematic, Donald says, that ambitious (OK?) female students may have a tough time persuading professors to choose appropriately gender-neutral verbiage.

“I consider it might turn out to be distinctly awkward to stand over the supervisor, who is about to draft your letter of reference, pointing out that what they write shouldn’t be gendered and asking them if they could please include lots of superlatives,” Doanld writes. “It could be seen as pretty pushy if not downright offensive!”

To avoid coming across as bossy—or is that a banned word now?—Donald suggests a few quick fixes. Concerned students could bring up the problem of gendered language in letters of recommendation in class, deliberately doing it “weeks/months in advance.” And science departments could also send professors reminders about “the possibility of double standards in adjectives and nouns peppering references.”

Jillian Kay Melchior writes for Heat Street and is a fellow for the Steamboat Institute and the Independent Women’s Forum.