diff --git a/builtins.cpp b/builtins.cpp
index 0e34596d..3738858f 100644
--- a/builtins.cpp
+++ b/builtins.cpp
@@ -411,12 +411,16 @@ lSetInternalFunctions(llvm::Module *module) {
         "__extract_int64",
         "__extract_int8",
         "__fastmath",
+        "__float_to_half_uniform",
+        "__float_to_half_varying",
         "__floatbits_uniform_int32",
         "__floatbits_varying_int32",
         "__floor_uniform_double",
         "__floor_uniform_float",
         "__floor_varying_double",
         "__floor_varying_float",
+        "__half_to_float_uniform",
+        "__half_to_float_varying",
         "__insert_int16",
         "__insert_int32",
         "__insert_int64",