diff --git a/configure.ac b/configure.ac
index 2ac1f2ec6..4a40762ca 100644
--- a/configure.ac
+++ b/configure.ac
@@ -608,7 +608,7 @@ AC_ARG_WITH(khronos-spec-dir, AS_HELP_STRING([--with-khronos-spec-dir=PATH], [Pa
 dnl Extensions.
 AC_ARG_ENABLE(registry,       AS_HELP_STRING([--disable-registry], [Build string registry module (default: enabled)]), [XREGISTRY=$enableval], [XREGISTRY=yes])
 AC_ARG_ENABLE(composite,      AS_HELP_STRING([--disable-composite], [Build Composite extension (default: enabled)]), [COMPOSITE=$enableval], [COMPOSITE=yes])
-AC_ARG_ENABLE(mitshm,         AS_HELP_STRING([--disable-shm], [Build SHM extension (default: enabled)]), [MITSHM=$enableval], [MITSHM=yes])
+AC_ARG_ENABLE(mitshm,         AS_HELP_STRING([--disable-mitshm], [Build SHM extension (default: enabled)]), [MITSHM=$enableval], [MITSHM=yes])
 AC_ARG_ENABLE(xres,           AS_HELP_STRING([--disable-xres], [Build XRes extension (default: enabled)]), [RES=$enableval], [RES=yes])
 AC_ARG_ENABLE(record,         AS_HELP_STRING([--disable-record], [Build Record extension (default: enabled)]), [RECORD=$enableval], [RECORD=yes])
 AC_ARG_ENABLE(xv,             AS_HELP_STRING([--disable-xv], [Build Xv extension (default: enabled)]), [XV=$enableval], [XV=yes])