diff --git a/test_conformance/math_brute_force/i_unary_float.cpp b/test_conformance/math_brute_force/i_unary_float.cpp
index 6d04a248..6b4a0f8c 100644
--- a/test_conformance/math_brute_force/i_unary_float.cpp
+++ b/test_conformance/math_brute_force/i_unary_float.cpp
@@ -31,7 +31,7 @@ static int BuildKernel(const char *name, int vectorSize, cl_kernel *k,
                         sizeNames[vectorSize],
                         "* in)\n"
                         "{\n"
-                        "   int i = get_global_id(0);\n"
+                        "   size_t i = get_global_id(0);\n"
                         "   out[i] = ",
                         name,
                         "( in[i] );\n"