OPINION
This is a diversity action, arising under Ohio law, in which a coin dealer asserts a claim under a property insurance policy for the value of certain coins and currency *582 stolen from an automobile. The district court granted summary judgment in favor of the defendants. Having concluded on de novo review that the plaintiff, as a matter of law, was not “actually in or upon” the vehicle when the theft occurred — and that the loss was thus not covered by reason of the plain language of an exclusionary clause containing this phrase — we shall affirm the judgment entered by the district court.
I
Thomas Noe is president of the plaintiff in this action, Thomas Noe, Inc., doing business in Maumee, Ohio, as Vintage Coins & Cards. Mr. Noe has been in the coin business since 1973.
On the evening of November 30, 1996, Mr. Noe and his wife were returning home from Dearborn, Michigan, after attending the annual convention of the Michigan State Numismatic Society. Mr. Noe had exhibited coins for sale at the convention. On the back seat of the Noes’ 1995 Oldsmobile Cutlass sedan — in briefcases 1 over which Mrs. Noe’s coat had been draped— was $203,588 worth of coins and currency belonging to the plaintiff.
Mr. and Mrs. Noe had originally planned to return this property to the coin store in Maumee before driving 1 to their home in Waterville, Ohio. Before they reached Maumee, however, Mrs. Noe spoke by cellular phone with her niece, Jennifer Bennett, who was watching after Mrs. Noe’s three children for the weekend. Jennifer was at Mrs. Noe’s sister’s house, with the children, in Sylvania, Ohio. Mr. and Mrs. Noe changed their plans and drove to Sylvania to pick up the children. The driving time from the convention site in Dearborn to the sister’s house in Sylva-nia was a little less than an hour.
Upon reaching the house in Sylvania, Mr. Noe pulled into the driveway and parked behind a van that Jennifer was using for the weekend. Another car was also standing in the driveway. The Noes retrieved a cassette tape out of the trunk of the Cutlass, and Mrs. Noe proceeded to the side-door of the house — a distance of twenty to twenty-five feet. A floodlight illuminated the driveway.
Mr. Noe locked the car doors with a remote control device, after which he checked every door individually to make sure it was locked. He then followed his wife into the house. Thex*e he greeted and hugged his stepchildren, standing where he could watch the car through the door at the side of the house. He subsequently helped the children get their shoes and coats on, and at one point he went back out to the driveway to get a child’s coat out of the van.
Angel Bennett, another of Mrs. Noe’s nieces, came in the side door a little later and asked what the commotion was on the street. Mr. Noe looked outside and saw nothing, but nonetheless went to check on the car. What he found was that the rear passenger window had been smashed and the company briefcases removed. Mr. Noe’s personal briefcase was also taken, but Mrs. Noe’s coat and purse, a duffle bag, a cellular phone and a radar detector remained undisturbed. The car doors were still locked. Mr. Noe did not see anyone driving or running away from the scene. The total time elapsing between the locking of the car doors and the discovery of the. theft was said to have been three to five minutes.
About a month and a half before the theft, the plaintiff had purchased a policy of insurance from defendant Homestead Insurance Company through defendant North American Collectibles Association. The policy, which included coverage for the loss of inventory by way of theft, had gone into effect on October 17,1996.
*583 The plaintiff made a timely claim under the policy. Homestead denied coverage, citing two different exclusionary clauses:
“5. PERILS EXCLUDED: The policy does not insure against loss or damage caused by:
D. Loss or damage to property while in or upon any vehicle unless at the time the loss occurs, there is actually in or upon such vehicle, the insured, a permanent employee of the insured, or a person whose sole duty is to attend this vehicle only. This does not apply to property in the custody of the U.S. Postal Service.
I. Theft from any automobile, motorcycle or other vehicle, occurring while such vehicles are unattended.”
The district court concluded that both clauses barred coverage, and summary judgment was granted to the defendants on that basis.
II
Where an exclusionary clause in an insurance contract is unambiguous, Ohio law requires that the plain language of the clause be given effect.
Park-Ohio Indus., Inc. v. Home Indem. Co.,
We conclude the exclusion contained in § 5.D of the policy does apply here as a matter of law. A man who is actually in a house tending to his stepchildren is not “actually in or upon” a vehicle parked outside the house. In its application to the facts before us, the language of § 5.D is simply not ambiguous — and the language must be applied in accordance with its terms. In light of our conclusion as to § 5.D, we see no need to consider whether the Noes’ Cutlass was “unattended” within the meaning of Exclusionary Clause § 5.1.
Recognizing that there is no binding Ohio precedent directly in point, the plaintiff relies heavily on an unreported decision in
Gottlieb & Sons, Inc. v. Hanover Ins. Co.,
No. 64559,
The factual situation in Gottlieb was one in which an employee of the insured was fourteen paces from the car and could see the vehicle as he inquired in a hotel lobby about the availability of a room. The employee saw a thief enter the car, and the employee managed to grab the back of the vehicle as it pulled away. Mr. Noe, in contrast, neither heard nor saw the theft. This means, as we see it, that he was not within a reasonable geographic perimeter around his car. Nothing in Gottlieb persuades us that § 5.D is inapplicable here.
Ill
The plaintiff contends that the trial court erred in failing to consider the affidavit of an expert witness, Professor Beth Eisler of the University of Toledo College of Law. Professor Eisler’s affidavit opines that both of the exclusionary clauses in *584 question here are ambiguous, and it suggests that “reasonable minds may differ as to whether Mr. Noe was ‘actually in or upon’ the vehicle or was ‘attending’ the vehicle.”
Given our conclusion that Exclusionary Clause 5.D is unambiguous, it is clear that evidence of a law professor’s contrary conclusion is inadmissible. See
North Am. Specialty Ins. Co. v. Myers,
AFFIRMED.
Notes
. Mr. and Mrs. Noe differ on the number of briefcases involved: Mr. Noe recalls two briefcases and Mrs. Noe recalls only one.
. The plaintiff also relies on
JMP Assocs., Inc. v. St. Paul Fire & Marine Ins. Co.,