diff --git a/README.md b/README.md
index 54e3cbf..84624bf 100644
--- a/README.md
+++ b/README.md
@@ -37,8 +37,7 @@
 
 * Python >= 3.6
 * Pip3
-* GNU toolchain (GCC, Binutils and libraries) or alternative C compiler/linker
-toolchain
+* GNU toolchain (GCC, Binutils and libraries)
 
 And optionally:
 
@@ -105,6 +104,16 @@
 recommended to install Vela along with the pre-commit tools (see
 [Vela Testing](TESTING.md) for more details).
 
+### `mlw_codec`
+
+As part of the installation process, Vela will compile a C based module.
+
+The build flags used for this module are as follows:
+
+```none
+-Wall -Werror -Wno-unused-function -Wno-unused-variable
+```
+
 ## Running
 
 Vela is run with an input `.tflite` file passed on the command line.  This file
diff --git a/ethosu/mlw_codec/makefile b/ethosu/mlw_codec/makefile
index 6eb418d..68eb0d9 100644
--- a/ethosu/mlw_codec/makefile
+++ b/ethosu/mlw_codec/makefile
@@ -20,7 +20,7 @@
 
 UNAME=$(shell uname -o)
 
-CFLAGS=-Wall -Wno-unused-function -Wno-unused-variable
+CFLAGS=-Wall -Werror -Wno-unused-function -Wno-unused-variable
 
 ifeq ($(DEBUG),1)
     CFLAGS+=-g -O0 -DDEBUG