diff --git a/labs/kernel-beagleplay-serial-dma/kernel-beagleplay-serial-dma.tex b/labs/kernel-beagleplay-serial-dma/kernel-beagleplay-serial-dma.tex
index bdde181ee8..ad5267181f 100644
--- a/labs/kernel-beagleplay-serial-dma/kernel-beagleplay-serial-dma.tex
+++ b/labs/kernel-beagleplay-serial-dma/kernel-beagleplay-serial-dma.tex
@@ -211,7 +211,7 @@ \section{Process user write requests}
 \begin{verbatim}
 struct dma_async_tx_descriptor *desc;
 
-desc = dmaengine_prep_slave_single(serial->txchan, serial->dma_addr,
+desc = dmaengine_prep_slave_single(serial->txchan, dma_addr,
                                    len, DMA_MEM_TO_DEV,
                                    DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
 if (!desc) ...
diff --git a/labs/kernel-serial-dma/kernel-serial-dma.tex b/labs/kernel-serial-dma/kernel-serial-dma.tex
index e93443bd28..73026d93c4 100644
--- a/labs/kernel-serial-dma/kernel-serial-dma.tex
+++ b/labs/kernel-serial-dma/kernel-serial-dma.tex
@@ -216,7 +216,7 @@ \section{Process user write requests}
 \begin{verbatim}
 struct dma_async_tx_descriptor *desc;
 
-desc = dmaengine_prep_slave_single(serial->txchan, serial->dma_addr + 1,
+desc = dmaengine_prep_slave_single(serial->txchan, dma_addr + 1,
                                    len - 1, DMA_MEM_TO_DEV,
                                    DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
 if (!desc) ...