diff --git a/ports/nrf/README.md b/ports/nrf/README.md
index 32907f2871..6c77774888 100644
--- a/ports/nrf/README.md
+++ b/ports/nrf/README.md
@@ -54,7 +54,7 @@ By default, the PCA10040 (nrf52832) is used as compile target. To build and flas
 Alternatively the target board could be defined:
 
      make BOARD=pca10040
-     make flash
+     make BOARD=pca10040 flash
      
 ## Compile and Flash with Bluetooth Stack