diff --git a/pkgs/development/libraries/ctl/default.nix b/pkgs/development/libraries/ctl/default.nix
index 950fe1baf08..1020ba3502e 100644
--- a/pkgs/development/libraries/ctl/default.nix
+++ b/pkgs/development/libraries/ctl/default.nix
@@ -8,12 +8,12 @@ stdenv.mkDerivation {
     sha256 = "16lzgbpxdyhykdwndj1i9vx3h4bfkxqqcrvasvgg70gb5raxj0mj";
   };
 
-  patches = [ ./patch.patch ];
-  
+  patches = [ ./patch.patch ./gcc47.patch ];
+
   propagatedBuildInputs = [ ilmbase ];
-  
+
   configureFlags = "--with-ilmbase-prefix=${ilmbase}";
-  
+
   #configurePhase = "
     #export CXXFLAGS=\"-I${ilmbase}/include -L${ilmbase}/lib\"
     #echo $CXXFLAGS
diff --git a/pkgs/development/libraries/ctl/gcc47.patch b/pkgs/development/libraries/ctl/gcc47.patch
new file mode 100644
index 00000000000..1aa4be4fe6d
--- /dev/null
+++ b/pkgs/development/libraries/ctl/gcc47.patch
@@ -0,0 +1,15 @@
+ https://bugs.gentoo.org/426368
+ 
+ IlmCtl/CtlInterpreter.cpp | 1 +
+ 1 file changed, 1 insertion(+)
+
+--- a/IlmCtl/CtlInterpreter.cpp
++++ b/IlmCtl/CtlInterpreter.cpp
+@@ -64,6 +64,7 @@
+ #include <fstream>
+ #include <algorithm>
+ #include <cassert>
++#include <unistd.h>
+ 
+ #ifdef WIN32
+     #include <io.h>