diff --git a/stb_image.h b/stb_image.h
index d0fa9c21eafb61a645be06abced432d109a74724..ea5cc9f2ae7cf1ca0503257edf724c5652711d81 100644
--- a/stb_image.h
+++ b/stb_image.h
@@ -1153,6 +1153,7 @@ STBIDEF int      stbi_is_hdr_from_file(FILE *f)
    stbi__start_file(&s,f);
    return stbi__hdr_test(&s);
    #else
+   STBI_NOTUSED(f);
    return 0;
    #endif
 }
@@ -1165,6 +1166,8 @@ STBIDEF int      stbi_is_hdr_from_callbacks(stbi_io_callbacks const *clbk, void
    stbi__start_callbacks(&s, (stbi_io_callbacks *) clbk, user);
    return stbi__hdr_test(&s);
    #else
+   STBI_NOTUSED(clbk);
+   STBI_NOTUSED(user);
    return 0;
    #endif
 }