diff --git a/pkgs/development/libraries/ignition-transport/generic.nix b/pkgs/development/libraries/ignition-transport/generic.nix
index 0b10c2cdb52..5edbf9e4551 100644
--- a/pkgs/development/libraries/ignition-transport/generic.nix
+++ b/pkgs/development/libraries/ignition-transport/generic.nix
@@ -15,6 +15,10 @@ stdenv.mkDerivation rec {
 
   propagatedBuildInputs = [ cppzmq ];
 
+  postPatch = ''
+    substituteInPlace cmake/ignition-config.cmake.in --replace "@CMAKE_INSTALL_PREFIX@/@CMAKE_INSTALL_" "@CMAKE_INSTALL_"
+  '';
+
   meta = with stdenv.lib; {
     homepage = http://ignitionrobotics.org/libraries/math;
     description = "Math library by Ingition Robotics, created for the Gazebo project";
diff --git a/pkgs/development/libraries/sdformat/default.nix b/pkgs/development/libraries/sdformat/default.nix
index a81ba17a3f5..692de29afd7 100644
--- a/pkgs/development/libraries/sdformat/default.nix
+++ b/pkgs/development/libraries/sdformat/default.nix
@@ -16,6 +16,10 @@ stdenv.mkDerivation rec {
 
   inherit name;
 
+  prePatch = ''
+    substituteInPlace cmake/sdf_config.cmake.in --replace "@CMAKE_INSTALL_PREFIX@/@LIB_INSTALL_DIR@" "@LIB_INSTALL_DIR@"
+  '';
+
   enableParallelBuilding = true;
   buildInputs = [
     cmake boost ruby ignition.math2 tinyxml