diff --git a/cmake/pkg-config.pc.in b/cmake/pkg-config.pc.in
index 3541abf0b..d36317f09 100644
--- a/cmake/pkg-config.pc.in
+++ b/cmake/pkg-config.pc.in
@@ -1,4 +1,4 @@
 Name: ${PROJECT_NAME}
 Description: JSON for Modern C++
 Version: ${PROJECT_VERSION}
-Cflags: -I${CMAKE_INSTALL_PREFIX}/${CMAKE_INSTALL_INCLUDEDIR}
+Cflags: -I${CMAKE_INSTALL_FULL_INCLUDEDIR}