diff --git a/octave-abs.patch b/octave-abs.patch
new file mode 100644
index 0000000..e7059f3
--- /dev/null
+++ b/octave-abs.patch
@@ -0,0 +1,27 @@
+diff -up octave-4.0.0/libinterp/corefcn/pr-output.cc.abs octave-4.0.0/libinterp/corefcn/pr-output.cc
+--- octave-4.0.0/libinterp/corefcn/pr-output.cc.abs	2015-05-23 08:21:53.000000000 -0600
++++ octave-4.0.0/libinterp/corefcn/pr-output.cc	2016-02-21 08:59:30.966291273 -0700
+@@ -21,7 +21,7 @@ along with Octave; see the file COPYING.
+ */
+ 
+ #ifdef HAVE_CONFIG_H
+-#include <config.h>
++#include "config.h"
+ #endif
+ 
+ #include <cfloat>
+@@ -3145,6 +3145,14 @@ PRINT_INT_SCALAR_INTERNAL (uint32_t)
+ PRINT_INT_SCALAR_INTERNAL (int64_t)
+ PRINT_INT_SCALAR_INTERNAL (uint64_t)
+ 
++inline unsigned int abs (unsigned int x) { return x; }
++inline long unsigned int abs (long unsigned int x) { return x; }
++inline long long unsigned int abs (long long unsigned int x) { return x; }
++inline short unsigned int abs (short unsigned int x) { return x; }
++inline unsigned char abs (unsigned char x) { return x; }
++inline signed char abs (signed char x) { return abs((int)x); }
++inline short int abs (short int x) { return abs((int)x); }
++
+ template <class T>
+ /* static */ inline void
+ octave_print_internal_template (std::ostream& os, const intNDArray<T>& nda,
diff --git a/octave-gnulib.patch b/octave-gnulib.patch
new file mode 100644
index 0000000..e83fb15
--- /dev/null
+++ b/octave-gnulib.patch
@@ -0,0 +1,11 @@
+diff -up octave-4.0.0/liboctave/cruft/Faddeeva/Faddeeva.hh.gnulib octave-4.0.0/liboctave/cruft/Faddeeva/Faddeeva.hh
+--- octave-4.0.0/liboctave/cruft/Faddeeva/Faddeeva.hh.gnulib	2015-05-23 08:21:53.000000000 -0600
++++ octave-4.0.0/liboctave/cruft/Faddeeva/Faddeeva.hh	2016-02-19 19:50:04.693811663 -0700
+@@ -27,6 +27,7 @@
+ #ifndef FADDEEVA_HH
+ #define FADDEEVA_HH 1
+ 
++#include <math.h>
+ #include <complex>
+ 
+ namespace Faddeeva {
diff --git a/octave-signbit.patch b/octave-signbit.patch
new file mode 100644
index 0000000..522f42a
--- /dev/null
+++ b/octave-signbit.patch
@@ -0,0 +1,12 @@
+diff -up octave-4.0.0/libgnu/math.in.h.signbit octave-4.0.0/libgnu/math.in.h
+--- octave-4.0.0/libgnu/math.in.h.signbit	2016-02-19 19:16:24.525856660 -0700
++++ octave-4.0.0/libgnu/math.in.h	2016-02-19 19:32:27.001262926 -0700
+@@ -2205,7 +2205,7 @@ _GL_WARN_REAL_FLOATING_DECL (isnan);
+ 
+ 
+ #if @GNULIB_SIGNBIT@
+-# if @REPLACE_SIGNBIT_USING_GCC@
++# if @REPLACE_SIGNBIT_USING_GCC@ && !defined(__cplusplus)
+ #  undef signbit
+    /* GCC 4.0 and newer provides three built-ins for signbit.  */
+ #  define signbit(x) \
diff --git a/octave.spec b/octave.spec
index 8f96239..8631f95 100644
--- a/octave.spec
+++ b/octave.spec
@@ -20,7 +20,7 @@
 Name:           octave
 Epoch:          6
 Version:        4.0.0
-Release:        12%{?dist}
+Release:        13%{?dist}
 Summary:        A high-level language for numerical computations
 Group:          Applications/Engineering
 License:        GPLv3+
@@ -43,6 +43,13 @@ Patch1:         octave-texinfo6-2ec049e50ed8.patch
 # Remove project_group from appdata.xml file
 # https://bugzilla.redhat.com/show_bug.cgi?id=1293561
 Patch2:         octave-appdata.patch
+# Fix gnulib signbit for g++ 6
+# https://bugzilla.redhat.com/show_bug.cgi?id=1276893
+Patch3:         octave-signbit.patch
+# Add needed #include <math.h> to bring in gnulib
+Patch4:         octave-gnulib.patch
+# Handle g++ 6 abs() change
+Patch5:         octave-abs.patch
 
 Provides:       octave(api) = %{octave_api}
 Provides:       bundled(gnulib)
@@ -165,6 +172,11 @@ This package contains documentation for Octave.
 rm doc/texinfo.tex
 %endif
 %patch2 -p1 -b .appdata
+%patch3 -p1 -b .signbit
+%patch4 -p1 -b .gnulib
+%patch5 -p1 -b .abs
+# Explicitly use gnulib headers
+find -name \*.cc -o -name \*.h -o -name \*.yy | xargs sed -i -e 's/#include <c\(math\|stdlib\)>/#include <\1.h>/'
 find -name \*.h -o -name \*.cc | xargs sed -i -e 's/<config.h>/"config.h"/' -e 's/<base-list.h>/"base-list.h"/'
 
 # Check permissions
@@ -398,6 +410,9 @@ fi
 %{_pkgdocdir}/refcard*.pdf
 
 %changelog
+* Sun Feb 21 2016 Orion Poplawski <orion@cora.nwra.com> - 6:4.0.0-13
+- Fix build with gcc 6
+
 * Thu Feb 18 2016 Orion Poplawski <orion@cora.nwra.com> - 6:4.0.0-12
 - Rebuild for glpk 4.58