diff --git a/bullet.pc.cmake b/bullet.pc.cmake
index 2863ca1f9..8b989faba 100644
--- a/bullet.pc.cmake
+++ b/bullet.pc.cmake
@@ -3,4 +3,4 @@ Description: Bullet Continuous Collision Detection and Physics Library
 Requires:
 Version: @BULLET_VERSION@
 Libs: -L@CMAKE_INSTALL_PREFIX@/@LIB_DESTINATION@ -lBulletSoftBody -lBulletDynamics -lBulletCollision -lLinearMath
-Cflags: @BULLET_DOUBLE_DEF@ -I@INCLUDE_INSTALL_DIR@ -I@CMAKE_INSTALL_PREFIX@/include
+Cflags: @BULLET_DOUBLE_DEF@ -I@CMAKE_INSTALL_PREFIX@/@INCLUDE_INSTALL_DIR@ -I@CMAKE_INSTALL_PREFIX@/include