diff --git a/docs/getting_started/build-options.rst b/docs/getting_started/build-options.rst
index ccaa40c..ecb32c1 100644
--- a/docs/getting_started/build-options.rst
+++ b/docs/getting_started/build-options.rst
@@ -272,6 +272,7 @@
    RMM_STATIC_ANALYSIS		,			,			,"Enable static analysis checkers"
    PLAT_CMN_CTX_MAX_XLAT_TABLES ,			,0			,"Maximum number of translation tables used by the runtime context"
    PLAT_CMN_EXTRA_MMAP_REGIONS	,			,0			,"Extra platform mmap regions that need to be mapped in S1 xlat tables"
+   PLAT_CMN_VIRT_ADDR_SPACE_WIDTH,			,38			,"Stage 1 Virtual address space width in bits for this platform"
    RMM_NUM_PAGES_PER_STACK	,			,5			,"Number of pages to use per CPU stack"
    MBEDTLS_ECP_MAX_OPS		,248 -			,1000			,"Number of max operations per ECC signing iteration"
    RMM_FPU_USE_AT_REL2		,ON | OFF		,OFF(fake_host) ON(aarch64),"Enable FPU/SIMD usage in RMM."