diff --git a/NAMESPACE b/NAMESPACE
index b438428..5c40bf3 100644
--- a/NAMESPACE
+++ b/NAMESPACE
@@ -1,8 +1,14 @@
 # Generated by roxygen2: do not edit by hand
 
 S3method(base::as.character,vctrs_rcrd)
+S3method(collapse::fmean,integer64)
+S3method(collapse::fmedian,integer64)
+S3method(collapse::fnobs,integer64)
+S3method(collapse::fnth,integer64)
+S3method(collapse::fsd,integer64)
 S3method(collapse::funique,POSIXlt)
 S3method(collapse::funique,vctrs_rcrd)
+S3method(collapse::fvar,integer64)
 S3method(cut,integer64)
 S3method(is_na,POSIXlt)
 S3method(is_na,data.frame)
diff --git a/R/factors.R b/R/factors.R
index c958880..8934f63 100644
--- a/R/factors.R
+++ b/R/factors.R
@@ -75,8 +75,6 @@ factor_ <- function(
   if (inherits(lvls, "data.frame")){
     fct_lvls <- do.call(paste, c(lvls, list(sep = "_")))
   } else if (is_int64){
-    # fct_lvls <- formatC(lvls, format = "f", drop0trailing = TRUE)
-    # fct_lvls <- format(lvls, scientific = FALSE, trim = TRUE)
     fct_lvls <- cpp_format_numeric_as_int64(lvls)
     } else {
     fct_lvls <- as.character(lvls)
diff --git a/R/utils.R b/R/utils.R
index 341019e..265969d 100644
--- a/R/utils.R
+++ b/R/utils.R
@@ -141,6 +141,31 @@ funique.POSIXlt <- function(x, sort = FALSE, ...){
   out
 }
 
+#' @exportS3Method collapse::fmean
+fmean.integer64 <- function(x, ...){
+  collapse::fmean(cpp_int64_to_double(x), ...)
+}
+#' @exportS3Method collapse::fmedian
+fmedian.integer64 <- function(x, ...){
+  collapse::fmedian(cpp_int64_to_double(x), ...)
+}
+#' @exportS3Method collapse::fvar
+fvar.integer64 <- function(x, ...){
+  collapse::fvar(cpp_int64_to_double(x), ...)
+}
+#' @exportS3Method collapse::fsd
+fsd.integer64 <- function(x, ...){
+  collapse::fsd(cpp_int64_to_double(x), ...)
+}
+#' @exportS3Method collapse::fnth
+fnth.integer64 <- function(x, ...){
+  collapse::fnth(cpp_int64_to_double(x), ...)
+}
+#' @exportS3Method collapse::fnobs
+fnobs.integer64 <- function(x, ...){
+  collapse::fnobs(cpp_int64_to_double(x), ...)
+}
+
 n_dots <- function(...){
   nargs()
 }
diff --git a/src/attrs.cpp b/src/attrs.cpp
index aa5b2e3..c5084db 100644
--- a/src/attrs.cpp
+++ b/src/attrs.cpp
@@ -41,7 +41,9 @@ SEXP cpp_set_rm_attr(SEXP x, SEXP which) {
 [[cpp11::register]]
 SEXP cpp_set_add_attributes(SEXP x, SEXP attributes, bool add) {
   int NP = 0;
-  if (Rf_isNull(attributes)){
+  if (Rf_isNull(attributes) ||
+      // is.null or empty list?
+      (TYPEOF(attributes) == VECSXP && Rf_length(attributes) == 0)){
     if (add){
       return x;
     } else {
diff --git a/src/scalars.cpp b/src/scalars.cpp
index 3ececbf..7d50d17 100644
--- a/src/scalars.cpp
+++ b/src/scalars.cpp
@@ -181,6 +181,36 @@ SEXP cpp_val_replace(SEXP x, SEXP value, SEXP replace, bool recursive){
     break;
   }
   case REALSXP: {
+    if (is_int64(x)){
+    SEXP temp = Rf_protect(Rf_allocVector(REALSXP, 0)); ++NP;
+    long long *p_out = INTEGER64_PTR(temp);
+
+    if (!is_int64(value)){
+      Rf_protect(value = Rf_coerceVector(value, REALSXP)); ++NP;
+      Rf_protect(value = cpp_numeric_to_int64(value)); ++NP;
+    }
+    if (!is_int64(replace)){
+      Rf_protect(replace = Rf_coerceVector(replace, REALSXP)); ++NP;
+      Rf_protect(replace = cpp_numeric_to_int64(replace)); ++NP;
+    }
+    long long val = INTEGER64_PTR(value)[0];
+    long long repl = INTEGER64_PTR(replace)[0];
+    long long *p_x = INTEGER64_PTR(x);
+    for (R_xlen_t i = 0; i < n; ++i){
+      eq = p_x[i] == val;
+      if (!any_eq && eq){
+        any_eq = true;
+        out = Rf_protect(Rf_duplicate(x)); ++NP;
+        // Change where pointer is pointing to
+        p_out = INTEGER64_PTR(out);
+      }
+      if (eq) p_out[i] = repl;
+    }
+    // Make sure to return x if there were no values to replace
+    if (!any_eq){
+      out = Rf_protect(x); ++NP;
+    }
+  } else {
     SEXP temp = Rf_protect(Rf_allocVector(REALSXP, 0)); ++NP;
     double *p_out = REAL(temp);
     Rf_protect(value = Rf_coerceVector(value, REALSXP)); ++NP;
@@ -219,7 +249,8 @@ SEXP cpp_val_replace(SEXP x, SEXP value, SEXP replace, bool recursive){
         out = Rf_protect(x); ++NP;
       }
     }
-    break;
+  }
+  break;
   }
   case STRSXP: {
     Rf_protect(value = Rf_coerceVector(value, STRSXP)); ++NP;