diff --git a/math/armadillo/Makefile b/math/armadillo/Makefile
index 7bd2a61ca139..5a8567083fa3 100644
--- a/math/armadillo/Makefile
+++ b/math/armadillo/Makefile
@@ -17,7 +17,6 @@ LIB_DEPENDS=	libarpack.so:math/arpack-ng \
 USES=		blaslapack:openblas cmake:testing compiler:c++11-lang pkgconfig tar:xz
 USE_LDCONFIG=	yes
 
-CMAKE_ARGS+=	-DPKG_CONFIG_DIR=${LOCALBASE}/libdata/pkgconfig/
 CMAKE_OFF=	BUILD_SMOKE_TEST
 CMAKE_TESTING_ON=	BUILD_SMOKE_TEST
 
diff --git a/math/armadillo/files/patch-CMakeLists.txt b/math/armadillo/files/patch-CMakeLists.txt
index 3166b0c89406..ad89f253e521 100644
--- a/math/armadillo/files/patch-CMakeLists.txt
+++ b/math/armadillo/files/patch-CMakeLists.txt
@@ -5,4 +5,4 @@
  configure_file(${PROJECT_BINARY_DIR}/tmp/misc/armadillo.pc.in "${PROJECT_BINARY_DIR}/tmp/misc/armadillo.pc" @ONLY)
  
 -install(FILES "${PROJECT_BINARY_DIR}/tmp/misc/armadillo.pc" DESTINATION ${CMAKE_INSTALL_LIBDIR}/pkgconfig)
-+install(FILES "${PROJECT_BINARY_DIR}/tmp/misc/armadillo.pc" DESTINATION ${PKG_CONFIG_DIR})
++install(FILES "${PROJECT_BINARY_DIR}/tmp/misc/armadillo.pc" DESTINATION ${CMAKE_INSTALL_PREFIX}/libdata/pkgconfig)