diff --git a/FindProj.cmake b/FindProj.cmake
index 4cb570f..7d10d9f 100644
--- a/FindProj.cmake
+++ b/FindProj.cmake
@@ -35,6 +35,7 @@ if(PROJ_FOUND)
     file(READ ${PROJ_INCLUDE_DIR}/proj.h proj_version)
     string(REGEX REPLACE "^.*PROJ_VERSION_MAJOR +([0-9]+).*$" "\\1" PROJ_VERSION_MAJOR "${proj_version}")
   elseif(EXISTS ${PROJ_INCLUDE_DIR}/proj_api.h)
+    file(READ ${PROJ_INCLUDE_DIR}/proj_api.h proj_version)
     string(REGEX REPLACE "^.*PJ_VERSION ([0-9]+).*$" "\\1" PJ_VERSION "${proj_version}")
     string(REGEX REPLACE "([0-9])([0-9])([0-9])" "\\1" PROJ_VERSION_MAJOR "${PJ_VERSION}")
   endif()