diff --git a/cmake/iOS.cmake b/cmake/iOS.cmake
index bb42802..4029f96 100644
--- a/cmake/iOS.cmake
+++ b/cmake/iOS.cmake
@@ -297,7 +297,7 @@
 
 # Set the find root to the iOS developer roots and to user defined paths.
 set(CMAKE_FIND_ROOT_PATH ${CMAKE_IOS_DEVELOPER_ROOT} ${CMAKE_OSX_SYSROOT}
-  ${CMAKE_PREFIX_PATH} CACHE string  "iOS find search path root" FORCE)
+  ${CMAKE_PREFIX_PATH} CACHE STRING  "iOS find search path root" FORCE)
 
 # Default to searching for frameworks first.
 set(CMAKE_FIND_FRAMEWORK FIRST)