diff --git a/cmake/test.cmake b/cmake/test.cmake
index b8b1250fb..5a5ce02ff 100644
--- a/cmake/test.cmake
+++ b/cmake/test.cmake
@@ -228,7 +228,7 @@ function(json_test_should_build_32bit_test build_32bit_var build_32bit_only_var
         # check if compiler is targeting 32bit by default
         include(CheckTypeSize)
         check_type_size("size_t" sizeof_size_t LANGUAGE CXX)
-        if(sizeof_size_t AND ${sizeof_size_t} EQUAL 4)
+        if(sizeof_size_t AND sizeof_size_t EQUAL 4)
             message(STATUS "Auto-enabling 32bit unit test.")
             set(${build_32bit_var} ON)
         else()