diff --git a/lib/mpi/mpi-div.c b/lib/mpi/mpi-div.c
index c3087d1..8a45717 100644
--- a/lib/mpi/mpi-div.c
+++ b/lib/mpi/mpi-div.c
@@ -149,6 +149,9 @@
 	mpi_ptr_t marker[5];
 	int markidx = 0;
 
+	if (!dsize)
+		return -EINVAL;
+
 	memset(marker, 0, sizeof(marker));
 
 	/* Ensure space is enough for quotient and remainder.