diff --git a/NEWS.md b/NEWS.md
index 472cc52dca..bc5a49b639 100644
--- a/NEWS.md
+++ b/NEWS.md
@@ -6,6 +6,8 @@
 
 ## BUG FIXES
 
+1. `gforce()` now allocates the correct amount of memory for the data.table with more than 1e9 rows, [#4295](https://github.com/Rdatatable/data.table/issues/4295) and [#4818](https://github.com/Rdatatable/data.table/issues/4818). Before the fixing, data.table could throw an error "Failed to allocate counts or TMP when assigning g in gforce", due to an integer overflow when `malloc()` memories. Thanks to @renkun-ken and @jangorecki for reporting and @shrektan for fixing.
+
 ## NOTES
 
 
diff --git a/src/gsumm.c b/src/gsumm.c
index 372ae59440..ed34e76207 100644
--- a/src/gsumm.c
+++ b/src/gsumm.c
@@ -112,7 +112,7 @@ SEXP gforce(SEXP env, SEXP jsub, SEXP o, SEXP f, SEXP l, SEXP irowsArg) {
     int highSize = ((nrow-1)>>shift) + 1;
     //Rprintf(_("When assigning grp[o] = g, highSize=%d  nb=%d  shift=%d  nBatch=%d\n"), highSize, nb, shift, nBatch);
     int *counts = calloc(nBatch*highSize, sizeof(int));  // TODO: cache-line align and make highSize a multiple of 64
-    int *TMP   = malloc(nrow*2*sizeof(int));
+    int *TMP   = malloc(nrow*2l*sizeof(int)); // must multiple the long int otherwise overflow may happen, #4295
     if (!counts || !TMP ) error(_("Internal error: Failed to allocate counts or TMP when assigning g in gforce"));
     #pragma omp parallel for num_threads(getDTthreads(nBatch, false))   // schedule(dynamic,1)
     for (int b=0; b<nBatch; b++) {