diff --git a/src/boot/part-discovery.c b/src/boot/part-discovery.c
index ab553a6530b..10ba5241254 100644
--- a/src/boot/part-discovery.c
+++ b/src/boot/part-discovery.c
@@ -60,7 +60,8 @@ static bool verify_gpt(/* const */ GptHeader *h, EFI_LBA lba_expected) {
         if (h->MyLBA != lba_expected)
                 return false;
 
-        if ((h->SizeOfPartitionEntry % sizeof(EFI_PARTITION_ENTRY)) != 0)
+        if (h->SizeOfPartitionEntry < sizeof(EFI_PARTITION_ENTRY) ||
+            (h->SizeOfPartitionEntry % sizeof(EFI_PARTITION_ENTRY)) != 0)
                 return false;
 
         if (h->NumberOfPartitionEntries <= 0 || h->NumberOfPartitionEntries > 1024)