diff --git a/net/core/sock.c b/net/core/sock.c
index 84ba3f67bca9..ec48690b5174 100644
--- a/net/core/sock.c
+++ b/net/core/sock.c
@@ -3817,7 +3817,7 @@ static int assign_proto_idx(struct proto *prot)
 {
 	prot->inuse_idx = find_first_zero_bit(proto_inuse_idx, PROTO_INUSE_NR);
 
-	if (unlikely(prot->inuse_idx == PROTO_INUSE_NR - 1)) {
+	if (unlikely(prot->inuse_idx == PROTO_INUSE_NR)) {
 		pr_err("PROTO_INUSE_NR exhausted\n");
 		return -ENOSPC;
 	}
@@ -3828,7 +3828,7 @@ static int assign_proto_idx(struct proto *prot)
 
 static void release_proto_idx(struct proto *prot)
 {
-	if (prot->inuse_idx != PROTO_INUSE_NR - 1)
+	if (prot->inuse_idx != PROTO_INUSE_NR)
 		clear_bit(prot->inuse_idx, proto_inuse_idx);
 }
 #else