diff --git a/drivers/misc/fastrpc.c b/drivers/misc/fastrpc.c
index ad6ced4546556..f3002653bd010 100644
--- a/drivers/misc/fastrpc.c
+++ b/drivers/misc/fastrpc.c
@@ -719,16 +719,18 @@ static int fastrpc_get_meta_size(struct fastrpc_invoke_ctx *ctx)
 static u64 fastrpc_get_payload_size(struct fastrpc_invoke_ctx *ctx, int metalen)
 {
 	u64 size = 0;
-	int i;
+	int oix;
 
 	size = ALIGN(metalen, FASTRPC_ALIGN);
-	for (i = 0; i < ctx->nscalars; i++) {
+	for (oix = 0; oix < ctx->nbufs; oix++) {
+		int i = ctx->olaps[oix].raix;
+
 		if (ctx->args[i].fd == 0 || ctx->args[i].fd == -1) {
 
-			if (ctx->olaps[i].offset == 0)
+			if (ctx->olaps[oix].offset == 0)
 				size = ALIGN(size, FASTRPC_ALIGN);
 
-			size += (ctx->olaps[i].mend - ctx->olaps[i].mstart);
+			size += (ctx->olaps[oix].mend - ctx->olaps[oix].mstart);
 		}
 	}