diff --git a/kdelibs-4.14.17-gcc6.patch b/kdelibs-4.14.17-gcc6.patch
index bdf82ea..f4048c7 100644
--- a/kdelibs-4.14.17-gcc6.patch
+++ b/kdelibs-4.14.17-gcc6.patch
@@ -1,6 +1,18 @@
+diff -up kdelibs-4.14.17/ConfigureChecks.cmake.gcc6 kdelibs-4.14.17/ConfigureChecks.cmake
+--- kdelibs-4.14.17/ConfigureChecks.cmake.gcc6	2016-02-11 23:06:08.000000000 -0600
++++ kdelibs-4.14.17/ConfigureChecks.cmake	2016-02-12 14:16:06.266544695 -0600
+@@ -244,7 +244,7 @@ check_prototype_exists(unsetenv stdlib.h
+ check_prototype_exists(usleep unistd.h              HAVE_USLEEP_PROTO)
+ check_prototype_exists(initgroups "unistd.h;sys/types.h;unistd.h;grp.h" HAVE_INITGROUPS_PROTO)
+ check_prototype_exists(setreuid unistd.h            HAVE_SETREUID_PROTO)
+-check_prototype_exists(trunc math.h                 HAVE_TRUNC)
++check_prototype_exists(truncf math.h                HAVE_TRUNC)
+ 
+ # check for existing datatypes
+ 
 diff -up kdelibs-4.14.17/solid/solid/backends/shared/cpufeatures.cpp.gcc6 kdelibs-4.14.17/solid/solid/backends/shared/cpufeatures.cpp
 --- kdelibs-4.14.17/solid/solid/backends/shared/cpufeatures.cpp.gcc6	2016-02-11 23:06:08.000000000 -0600
-+++ kdelibs-4.14.17/solid/solid/backends/shared/cpufeatures.cpp	2016-02-12 10:50:24.432992612 -0600
++++ kdelibs-4.14.17/solid/solid/backends/shared/cpufeatures.cpp	2016-02-12 12:57:35.726543228 -0600
 @@ -51,23 +51,23 @@ static void sighandler( int )
  #endif
  
diff --git a/kdelibs.spec b/kdelibs.spec
index 44c2ff6..86e42fc 100644
--- a/kdelibs.spec
+++ b/kdelibs.spec
@@ -470,10 +470,6 @@ pushd %{_target_platform}
   ..
 popd
 
-## HACK, https://bugzilla.redhat.com/show_bug.cgi?id=1307086#c2
-## assume we HAVE_TRUNC on fedora/linux
-sed -i -e 's|^/* #undef HAVE_TRUNC */|#define   HAVE_TRUNC 1|g' %{_target_platform}/config.h
-
 make %{?_smp_mflags} -C %{_target_platform}
 
 # build apidocs