diff --git a/libc/Makefile b/libc/Makefile
index b57e22ed..c2b4dfbd 100644
--- a/libc/Makefile
+++ b/libc/Makefile
@@ -357,6 +357,7 @@ time/clock_nanosleep.o \
time/clock.o \
time/clock_settime.o \
time/clock_settimeres.o \
+time/difftime.o \
time/nanosleep.o \
time/timens.o \
time/time.o \
diff --git a/libc/time/difftime.cpp b/libc/time/difftime.cpp
new file mode 100644
index 00000000..459e16cc
--- /dev/null
+++ b/libc/time/difftime.cpp
@@ -0,0 +1,30 @@
+/*******************************************************************************
+
+ Copyright(C) Jonas 'Sortie' Termansen 2013
+
+ This file is part of the Sortix C Library.
+
+ The Sortix C Library is free software: you can redistribute it and/or modify
+ it under the terms of the GNU Lesser General Public License as published by
+ the Free Software Foundation, either version 3 of the License, or (at your
+ option) any later version.
+
+ The Sortix C Library is distributed in the hope that it will be useful, but
+ WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
+ or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public
+ License for more details.
+
+ You should have received a copy of the GNU Lesser General Public License
+ along with the Sortix C Library. If not, see .
+
+ time/difftime.cpp
+ Calculate time difference.
+
+*******************************************************************************/
+
+#include
+
+extern "C" double difftime(time_t a, time_t b)
+{
+ return (double) (a - b);
+}