diff --git a/ChangeLog b/ChangeLog
index a0b58dfa8..6c6e55d4d 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -28,6 +28,7 @@
 - TW-1724 some commands show color codes when redirected (thanks to Alan Young).
 - TW-1729 zsh completion: zregexparse:4: not enough regex argument (thanks to
           Daniel Shahaf).
+- TW-1733 taskwarrior 2.5.0 can not compile FreeBSD 10.1 (thanks to ribbon).
 - TW-1738 add defined languages JAPANESE (thanks to ribbon).
 - Fixed broken build for Cygwin and older GCC (thanks to Richard Boß).
 - The default configuration is now 256-color only.
diff --git a/src/ISO8601.cpp b/src/ISO8601.cpp
index 870359346..085b5f975 100644
--- a/src/ISO8601.cpp
+++ b/src/ISO8601.cpp
@@ -1581,12 +1581,6 @@ bool ISO8601d::sameYear (const ISO8601d& rhs) const
   return this->year () == rhs.year ();
 }
 
-////////////////////////////////////////////////////////////////////////////////
-ISO8601d ISO8601d::operator+ (time_t delta)
-{
-  return ISO8601d (_date + delta);
-}
-
 ////////////////////////////////////////////////////////////////////////////////
 ISO8601d ISO8601d::operator+ (const int delta)
 {
diff --git a/src/ISO8601.h b/src/ISO8601.h
index ddc661914..4c23bf401 100644
--- a/src/ISO8601.h
+++ b/src/ISO8601.h
@@ -97,7 +97,6 @@ public:
   bool sameWeek   (const ISO8601d&) const;
   bool sameMonth  (const ISO8601d&) const;
   bool sameYear   (const ISO8601d&) const;
-  ISO8601d operator+  (time_t);
   ISO8601d operator+  (const int);
   ISO8601d operator-  (const int);
   ISO8601d& operator+= (const int);