diff --git a/cmake/lws_config.h.in b/cmake/lws_config.h.in
index d06c38c7c..8e0ce81bf 100644
--- a/cmake/lws_config.h.in
+++ b/cmake/lws_config.h.in
@@ -7,7 +7,7 @@
 #endif
 
 #define LWS_INSTALL_DATADIR "${CMAKE_INSTALL_PREFIX}/share"
-#define LWS_INSTALL_LIBDIR "${CMAKE_INSTALL_PREFIX}/${LWS_INSTALL_LIB_DIR}"
+#define LWS_INSTALL_LIBDIR "${CMAKE_INSTALL_FULL_LIBDIR}"
 #define LWS_PLUGIN_DIR "${LWS_INSTALL_PLUGIN_DIR}"
 #define LWS_LIBRARY_VERSION_MAJOR ${LWS_LIBRARY_VERSION_MAJOR}
 #define LWS_LIBRARY_VERSION_MINOR ${LWS_LIBRARY_VERSION_MINOR}
diff --git a/lib/CMakeLists.txt b/lib/CMakeLists.txt
index fedb0ed95..d30c2b07e 100644
--- a/lib/CMakeLists.txt
+++ b/lib/CMakeLists.txt
@@ -429,8 +429,8 @@ endif()
 file(WRITE "${PROJECT_BINARY_DIR}/libwebsockets.pc"
 "prefix=\"${CMAKE_INSTALL_PREFIX}\"
 exec_prefix=\${prefix}
-libdir=\${exec_prefix}/${LWS_INSTALL_LIB_DIR}
-includedir=\${prefix}/${LWS_INSTALL_INCLUDE_DIR}
+libdir=${CMAKE_INSTALL_FULL_LIBDIR}
+includedir=${CMAKE_INSTALL_FULL_INCLUDEDIR}
 
 Name: libwebsockets
 Description: Websockets server and client library
@@ -451,8 +451,8 @@ endif()
 file(WRITE "${PROJECT_BINARY_DIR}/libwebsockets_static.pc"
 "prefix=\"${CMAKE_INSTALL_PREFIX}\"
 exec_prefix=\${prefix}
-libdir=\${exec_prefix}/${LWS_INSTALL_LIB_DIR}
-includedir=\${prefix}/${LWS_INSTALL_INCLUDE_DIR}
+libdir=${CMAKE_INSTALL_FULL_LIBDIR}
+includedir=${CMAKE_INSTALL_FULL_INCLUDEDIR}
 
 Name: libwebsockets_static
 Description: Websockets server and client static library