diff --git a/checkin_notes b/checkin_notes
index 71c47bcfc4..4bd8c1c05f 100644
--- a/checkin_notes
+++ b/checkin_notes
@@ -5092,3 +5092,13 @@ David  25 Aug 2011
         validator.cpp
     html/user/
         various
+
+Charlie 26 Aug 2011
+    - lib: use standard implementation of strtoull when available.
+
+    configure.ac
+    clientgui/
+        mac/
+            config.h
+    lib/
+        parse.h
diff --git a/clientgui/mac/config.h b/clientgui/mac/config.h
index a82f3b4724..315c9e40b0 100644
--- a/clientgui/mac/config.h
+++ b/clientgui/mac/config.h
@@ -211,6 +211,9 @@
 /* Define to 1 if you have the `strcasestr' function. */
 #define HAVE_STRCASESTR 1
 
+/* Define to 1 if you have the `strtoull' function. */
+#define HAVE_STRTOULL 1
+
 /* Define to 1 if `tm_zone' is member of `struct tm'. */
 #define HAVE_STRUCT_TM_TM_ZONE 1
 
diff --git a/configure.ac b/configure.ac
index 2a3aaa9957..8c4193179d 100644
--- a/configure.ac
+++ b/configure.ac
@@ -655,7 +655,7 @@ AC_FUNC_ALLOCA
 if test "${ac_cv_func_alloca_works}" = "yes" ; then
   ac_cv_func_alloca="yes"
 fi
-AC_CHECK_FUNCS(alloca _alloca __builtin_alloca ether_ntoa setpriority sched_setscheduler strlcpy strlcat strcasestr strcasecmp sigaction getutent setutent getisax strdup strdupa daemon stat64 putenv setenv unsetenv res_init)
+AC_CHECK_FUNCS(alloca _alloca __builtin_alloca ether_ntoa setpriority sched_setscheduler strlcpy strlcat strcasestr strcasecmp sigaction getutent setutent getisax strdup strdupa daemon stat64 putenv setenv unsetenv res_init strtoull)
 
 dnl Checks for typedefs, structures, and compiler characteristics.
 AC_C_CONST
diff --git a/lib/parse.h b/lib/parse.h
index ec7304307b..3ab2672274 100644
--- a/lib/parse.h
+++ b/lib/parse.h
@@ -78,10 +78,10 @@ inline bool match_tag(const std::string &s, const char* tag) {
     return match_tag(s.c_str(), tag);
 }
 
-//TODO: use strtoull() when available
 #ifdef _WIN32
 #define boinc_strtoull _strtoui64
-#elif defined(__APPLE__)
+#else
+#ifdef HAVE_STRTOULL
 #define boinc_strtoull strtoull
 #else
 inline unsigned long long boinc_strtoull(const char *s, char **, int) {
@@ -100,6 +100,7 @@ inline unsigned long long boinc_strtoull(const char *s, char **, int) {
     return y;
 }
 #endif
+#endif
 
 // parse an integer of the form <tag>1234</tag>
 // return true if it's there