diff --git a/pkgs/desktops/kde/kdebase/default.nix b/pkgs/desktops/kde/kdebase/default.nix
index 77dc9889995..c550c228ed7 100644
--- a/pkgs/desktops/kde/kdebase/default.nix
+++ b/pkgs/desktops/kde/kdebase/default.nix
@@ -27,9 +27,23 @@ stdenv.mkDerivation {
     --with-extra-includes=${libjpeg}/include
   ";
 
+  # Prevent configure from looking for pkg-config and freetype-config
+  # in the wrong location (it looks in /usr/bin etc. *before* looking
+  # in $PATH).
+  preConfigure = ''
+    substituteInPlace configure \
+      --replace /usr/bin /no-such-path \
+      --replace /usr/local/bin /no-such-path \
+      --replace /opt/local/bin /no-such-path
+  '';
+
   # Quick hack to work around a faulty dependency in
   # konqueror/keditbookmarks/Makefile.am (${includedir} should be
   # ${kdelibs} or so).
-  preBuild = "ensureDir $out/include; ln -s ${kdelibs}/include/kbookmarknotifier.h $out/include/";
+  preBuild = ''
+    ensureDir $out/include
+    ln -s ${kdelibs}/include/kbookmarknotifier.h $out/include/
+  '';
+  
   postInstall = "rm $out/include/kbookmarknotifier.h";
 }
diff --git a/pkgs/desktops/kde/kdelibs/default.nix b/pkgs/desktops/kde/kdelibs/default.nix
index 9eb6625d45a..76c5f5cc3f5 100644
--- a/pkgs/desktops/kde/kdelibs/default.nix
+++ b/pkgs/desktops/kde/kdelibs/default.nix
@@ -21,6 +21,16 @@ stdenv.mkDerivation {
     libtool freetype bzip2 cups
   ];
 
+  # Prevent configure from looking for pkg-config and freetype-config
+  # in the wrong location (it looks in /usr/bin etc. *before* looking
+  # in $PATH).
+  preConfigure = ''
+    substituteInPlace configure \
+      --replace /usr/bin /no-such-path \
+      --replace /usr/local/bin /no-such-path \
+      --replace /opt/local/bin /no-such-path
+  '';
+
   configureFlags = "
     --without-arts 
     --with-ssl-dir=${openssl}