diff --git a/src/gerbil/core/runtime.ss b/src/gerbil/core/runtime.ss
index a5da24e759..b905a6a4e0 100644
--- a/src/gerbil/core/runtime.ss
+++ b/src/gerbil/core/runtime.ss
@@ -341,8 +341,14 @@ package: gerbil/core
   (extern namespace: #f
     ;; source: gambit.sld
     ;; procedures and globals provided by Gambit
+
+    ;; globals
     default-random-source
 
+    ;; macros
+    time
+
+    ;; procedures
     ->char-set
     abandoned-mutex-exception?
     abort
diff --git a/src/std/text/json/json-benchmark.ss b/src/std/text/json/json-benchmark.ss
index fe152347a8..2ea5885366 100644
--- a/src/std/text/json/json-benchmark.ss
+++ b/src/std/text/json/json-benchmark.ss
@@ -4,9 +4,7 @@
         ./api)
 (export main)
 
-(extern namespace: #f time)
-
-(def (main method file)
+((def (main method file)
   (parameterize ((json-symbolic-keys #t))
     (case method
       (("port") (benchmark-port file))