diff --git a/basis/present/present-docs.factor b/basis/present/present-docs.factor
index bda7723173..0428235c2a 100644
--- a/basis/present/present-docs.factor
+++ b/basis/present/present-docs.factor
@@ -8,6 +8,6 @@ ARTICLE: "present" "Converting objects to human-readable strings"
 HELP: present
 { $values { "object" object } { "string" string } }
 { $contract "Outputs a human-readable string from an object." }
-{ $notes "New methods can be defined by user code. Most often, this is done so that the object can be used with various words in the " { $vocab-link "html.components" } " or " { $link "urls" } " vocabularies." } ;
+{ $notes "New methods can be defined by user code. Most often, this is done so that the object can be used with various words in the " { $vocab-link "html.components" } " or " { $vocab-link "urls" } " vocabularies." } ;
 
 ABOUT: "present"
diff --git a/basis/threads/threads.factor b/basis/threads/threads.factor
index 5dca7be633..4332bbbcf5 100644
--- a/basis/threads/threads.factor
+++ b/basis/threads/threads.factor
@@ -89,7 +89,7 @@ PRIVATE>
     f >>state
     check-registered 2array run-queue push-front ;
 
-: sleep-time ( -- ms/f )
+: sleep-time ( -- us/f )
     {
         { [ run-queue deque-empty? not ] [ 0 ] }
         { [ sleep-queue heap-empty? ] [ f ] }
diff --git a/core/io/backend/backend.factor b/core/io/backend/backend.factor
index 0c13277106..5456f2251c 100644
--- a/core/io/backend/backend.factor
+++ b/core/io/backend/backend.factor
@@ -8,7 +8,7 @@ SYMBOL: io-backend
 
 SINGLETON: c-io-backend
 
-c-io-backend io-backend set-global
+io-backend global [ c-io-backend or ] change-at
 
 HOOK: init-io io-backend ( -- )
 
@@ -20,7 +20,7 @@ HOOK: (init-stdio) io-backend ( -- stdin stdout stderr )
     [ utf8 <encoder> output-stream set-global ]
     [ utf8 <encoder> error-stream set-global ] tri* ;
 
-HOOK: io-multiplex io-backend ( ms -- )
+HOOK: io-multiplex io-backend ( us -- )
 
 HOOK: normalize-directory io-backend ( str -- newstr )
 
diff --git a/core/system/system-docs.factor b/core/system/system-docs.factor
index 3adf82af7f..ab17ce2be9 100644
--- a/core/system/system-docs.factor
+++ b/core/system/system-docs.factor
@@ -12,6 +12,7 @@ ARTICLE: "system" "System interface"
 { $subsection image }
 "Getting the current time:"
 { $subsection micros }
+{ $subsection millis }
 "Exiting the Factor VM:"
 { $subsection exit } ;
 
@@ -70,7 +71,7 @@ HELP: micros ( -- us )
 { $notes "This is a low-level word. The " { $vocab-link "calendar" } " vocabulary provides features for date/time arithmetic and formatting." } ;
 
 HELP: millis ( -- ms )
-{ $values { "us" integer } }
+{ $values { "ms" integer } }
 { $description "Outputs the number of milliseconds ellapsed since midnight January 1, 1970." }
 { $notes "This is a low-level word. The " { $vocab-link "calendar" } " vocabulary provides features for date/time arithmetic and formatting." } ;