diff --git a/pkgs/development/compilers/gcc/4.6/default.nix b/pkgs/development/compilers/gcc/4.6/default.nix
index 6713dd12b3cd..faa5bba5e4a7 100644
--- a/pkgs/development/compilers/gcc/4.6/default.nix
+++ b/pkgs/development/compilers/gcc/4.6/default.nix
@@ -462,7 +462,7 @@ stdenv.mkDerivation ({
     # Volunteers needed for the {Cyg,Dar}win ports of *PPL.
     # gnatboot is not available out of linux platforms, so we disable the darwin build
     # for the gnat (ada compiler).
-    platforms = stdenv.lib.platforms.linux ++ optionals (langAda == false && libelf == null) [ "i686-darwin" ];
+    platforms = stdenv.lib.platforms.linux ++ optionals (langAda == false) stdenv.lib.platforms.darwin;
   };
 }
 
diff --git a/pkgs/development/libraries/gts/default.nix b/pkgs/development/libraries/gts/default.nix
index 7eb519a045c3..7724bc5cc3ab 100644
--- a/pkgs/development/libraries/gts/default.nix
+++ b/pkgs/development/libraries/gts/default.nix
@@ -23,6 +23,6 @@ stdenv.mkDerivation rec {
     '';
 
     maintainers = [ stdenv.lib.maintainers.viric ];
-    platforms = stdenv.lib.platforms.linux;
+    platforms = stdenv.lib.platforms.linux ++ stdenv.lib.platforms.darwin;
   };
 }
diff --git a/pkgs/development/libraries/harfbuzz/default.nix b/pkgs/development/libraries/harfbuzz/default.nix
index 1202ab5825d7..78e016c1582e 100644
--- a/pkgs/development/libraries/harfbuzz/default.nix
+++ b/pkgs/development/libraries/harfbuzz/default.nix
@@ -20,6 +20,6 @@ stdenv.mkDerivation rec {
     description = "An OpenType text shaping engine";
     homepage = http://www.freedesktop.org/wiki/Software/HarfBuzz;
     maintainers = [ stdenv.lib.maintainers.eelco ];
-    platforms = stdenv.lib.platforms.linux;
+    platforms = stdenv.lib.platforms.linux ++ stdenv.lib.platforms.darwin;
   };
 }
diff --git a/pkgs/development/libraries/libiconv/default.nix b/pkgs/development/libraries/libiconv/default.nix
index 7562765a3ac3..b286dcfcd199 100644
--- a/pkgs/development/libraries/libiconv/default.nix
+++ b/pkgs/development/libraries/libiconv/default.nix
@@ -39,6 +39,6 @@ stdenv.mkDerivation rec {
     maintainers = [ ];
 
     # This library is not needed on GNU platforms.
-    platforms = [ "i686-cygwin" ];
+    hydraPlatforms = stdenv.lib.platforms.cygwin ++ stdenv.lib.platforms.darwin ++ stdenv.lib.platforms.freebsd;
   };
 }
diff --git a/pkgs/development/libraries/libxml2/default.nix b/pkgs/development/libraries/libxml2/default.nix
index e25074f8d126..c2012a444394 100644
--- a/pkgs/development/libraries/libxml2/default.nix
+++ b/pkgs/development/libraries/libxml2/default.nix
@@ -33,7 +33,7 @@ stdenv.mkDerivation rec {
     homepage = http://xmlsoft.org/;
     description = "An XML parsing library for C";
     license = "bsd";
-    platforms = stdenv.lib.platforms.linux;
+    platforms = stdenv.lib.platforms.unix;
     maintainers = [ stdenv.lib.maintainers.eelco ];
   };
 }
diff --git a/pkgs/development/libraries/libxslt/default.nix b/pkgs/development/libraries/libxslt/default.nix
index ed56ffaff736..e2568af6c9bc 100644
--- a/pkgs/development/libraries/libxslt/default.nix
+++ b/pkgs/development/libraries/libxslt/default.nix
@@ -19,7 +19,7 @@ stdenv.mkDerivation (rec {
     homepage = http://xmlsoft.org/XSLT/;
     description = "A C library and tools to do XSL transformations";
     license = "bsd";
-    platforms = stdenv.lib.platforms.linux;
+    platforms = stdenv.lib.platforms.unix;
     maintainers = [ stdenv.lib.maintainers.eelco ];
   };
 } // (if !stdenv.isFreeBSD then {} else {
diff --git a/pkgs/development/libraries/pango/default.nix b/pkgs/development/libraries/pango/default.nix
index 99bf8f10fd82..ca1db1372064 100644
--- a/pkgs/development/libraries/pango/default.nix
+++ b/pkgs/development/libraries/pango/default.nix
@@ -36,6 +36,6 @@ stdenv.mkDerivation rec {
     license = "LGPLv2+";
 
     maintainers = with stdenv.lib.maintainers; [ raskin urkud ];
-    platforms = stdenv.lib.platforms.linux;
+    platforms = stdenv.lib.platforms.linux ++ stdenv.lib.platforms.darwin;
   };
 }
diff --git a/pkgs/development/libraries/sqlite/default.nix b/pkgs/development/libraries/sqlite/default.nix
index 7521abc599be..de96ab58eaef 100644
--- a/pkgs/development/libraries/sqlite/default.nix
+++ b/pkgs/development/libraries/sqlite/default.nix
@@ -20,6 +20,6 @@ stdenv.mkDerivation {
   meta = {
     homepage = http://www.sqlite.org/;
     description = "A self-contained, serverless, zero-configuration, transactional SQL database engine";
-    platforms = stdenv.lib.platforms.linux;
+    platforms = stdenv.lib.platforms.unix;
   };
 }
diff --git a/pkgs/development/perl-modules/DBD-SQLite/default.nix b/pkgs/development/perl-modules/DBD-SQLite/default.nix
index 332a3bd0e8f6..06688ded22a5 100644
--- a/pkgs/development/perl-modules/DBD-SQLite/default.nix
+++ b/pkgs/development/perl-modules/DBD-SQLite/default.nix
@@ -35,5 +35,5 @@ buildPerlPackage rec {
   # (e.g. "database is locked(5) at dbdimp.c line 402 at t/07busy.t").
   doCheck = false;
 
-  meta.platforms = stdenv.lib.platforms.linux;
+  meta.platforms = stdenv.lib.platforms.unix;
 }
diff --git a/pkgs/os-specific/linux/wpa_supplicant/gui.nix b/pkgs/os-specific/linux/wpa_supplicant/gui.nix
index 29591bf0335c..59a3c51c4d6e 100644
--- a/pkgs/os-specific/linux/wpa_supplicant/gui.nix
+++ b/pkgs/os-specific/linux/wpa_supplicant/gui.nix
@@ -37,6 +37,6 @@ stdenv.mkDerivation {
 
   meta = {
     description = "Qt-based GUI for wpa_supplicant";
-    inherit (qt4.meta) platforms;
+    platforms = stdenv.lib.platforms.linux;
   };
 }
diff --git a/pkgs/tools/graphics/graphviz/default.nix b/pkgs/tools/graphics/graphviz/default.nix
index c1aebd3dfe1a..0ef70a197d6f 100644
--- a/pkgs/tools/graphics/graphviz/default.nix
+++ b/pkgs/tools/graphics/graphviz/default.nix
@@ -53,7 +53,7 @@ stdenv.mkDerivation rec {
       interfaces for other technical domains.
     '';
 
-    platforms = stdenv.lib.platforms.linux;
+    platforms = stdenv.lib.platforms.linux ++ stdenv.lib.platforms.darwin;
     maintainers = with stdenv.lib.maintainers; [ simons bjornfor ];
   };
 }