diff --git a/llama.h b/llama.h
index 74f0e56de..e83fbe78b 100644
--- a/llama.h
+++ b/llama.h
@@ -117,6 +117,7 @@ extern "C" {
         LLAMA_FTYPE_MOSTLY_IQ2_S         = 28, // except 1d tensors
         LLAMA_FTYPE_MOSTLY_IQ2_M         = 29, // except 1d tensors
         LLAMA_FTYPE_MOSTLY_IQ4_XS        = 30, // except 1d tensors
+        LLAMA_FTYPE_MOSTLY_IQ1_XS        = 31, // except 1d tensors
 
         LLAMA_FTYPE_GUESSED = 1024, // not specified in the model file
     };