diff --git a/docs/getting_started/build-options.rst b/docs/getting_started/build-options.rst
index af2f797..9c525d7 100644
--- a/docs/getting_started/build-options.rst
+++ b/docs/getting_started/build-options.rst
@@ -272,6 +272,7 @@
    RMM_FPU_USE_AT_REL2		,ON | OFF		,OFF(fake_host) ON(aarch64),"Enable FPU/SIMD usage in RMM."
    RMM_MAX_GRANULES		,			,0			,"Maximum number of memory granules available to the system"
    HOST_VARIANT			,host_build | host_test	,host_build		,"Variant to build for the host platform. Only available when RMM_PLATFORM=host"
+   HOST_MEM_SIZE		,			,0x40000000		,"Host memory size that will be used as physical granules"
    RMM_COVERAGE 		,ON | OFF		,OFF			,"Enable coverage analysis"
    RMM_HTML_COV_REPORT		,ON | OFF		,ON			,"Enable HTML output report for coverage analysis"