diff --git a/FindMPFRCppThirdparty.cmake b/FindMPFRCppThirdparty.cmake
index c1f6efe..1797d17 100644
--- a/FindMPFRCppThirdparty.cmake
+++ b/FindMPFRCppThirdparty.cmake
@@ -8,7 +8,7 @@ if(MPFR_FOUND)
     INSTALL_DIR ${CMAKE_BINARY_DIR}/include
     CONFIGURE_COMMAND true
     BUILD_COMMAND true
-    INSTALL_COMMAND ${CMAKE_COMMAND} -E copy <SOURCE_DIR>/mpreal.h ${CMAKE_BINARY_DIR})
+    INSTALL_COMMAND ${CMAKE_COMMAND} -E copy <SOURCE_DIR>/mpreal.h <INSTALL_DIR>)
 endif()
 
 set(MPFRCPP_PREFIX  ${CMAKE_BINARY_DIR} CACHE FILEPATH "" FORCE)