diff --git a/http-push.c b/http-push.c
index 91a5465afb120e..7a9b96a6d0c9c9 100644
--- a/http-push.c
+++ b/http-push.c
@@ -208,7 +208,8 @@ static void curl_setup_http(CURL *curl, const char *url,
 	curl_easy_setopt(curl, CURLOPT_UPLOAD, 1L);
 	curl_easy_setopt(curl, CURLOPT_URL, url);
 	curl_easy_setopt(curl, CURLOPT_INFILE, buffer);
-	curl_easy_setopt(curl, CURLOPT_INFILESIZE, buffer->buf.len);
+	curl_easy_setopt(curl, CURLOPT_INFILESIZE_LARGE,
+			 cast_size_t_to_curl_off_t(buffer->buf.len));
 	curl_easy_setopt(curl, CURLOPT_READFUNCTION, fread_buffer);
 	curl_easy_setopt(curl, CURLOPT_SEEKFUNCTION, seek_buffer);
 	curl_easy_setopt(curl, CURLOPT_SEEKDATA, buffer);
diff --git a/http.h b/http.h
index 36202139f451ff..0a36dbd2949b56 100644
--- a/http.h
+++ b/http.h
@@ -8,6 +8,7 @@ struct packed_git;
 #include <curl/curl.h>
 #include <curl/easy.h>
 
+#include "gettext.h"
 #include "strbuf.h"
 #include "remote.h"
 
@@ -95,6 +96,15 @@ static inline int missing__target(int code, int result)
 
 #define missing_target(a) missing__target((a)->http_code, (a)->curl_result)
 
+static inline curl_off_t cast_size_t_to_curl_off_t(size_t a)
+{
+	uintmax_t size = a;
+	if (size > maximum_signed_value_of_type(curl_off_t))
+		die(_("number too large to represent as curl_off_t "
+		      "on this platform: %"PRIuMAX), (uintmax_t)a);
+	return (curl_off_t)a;
+}
+
 /*
  * Normalize curl results to handle CURL_FAILONERROR (or lack thereof). Failing
  * http codes have their "result" converted to CURLE_HTTP_RETURNED_ERROR, and
diff --git a/imap-send.c b/imap-send.c
index 4bd5b8aa0d7faf..26dda7f3287127 100644
--- a/imap-send.c
+++ b/imap-send.c
@@ -1721,7 +1721,7 @@ static int curl_append_msgs_to_imap(struct imap_server_conf *server,
 		lf_to_crlf(&msgbuf.buf);
 
 		curl_easy_setopt(curl, CURLOPT_INFILESIZE_LARGE,
-				 (curl_off_t)(msgbuf.buf.len-prev_len));
+				 cast_size_t_to_curl_off_t(msgbuf.buf.len-prev_len));
 
 		res = curl_easy_perform(curl);
 
diff --git a/remote-curl.c b/remote-curl.c
index 84f46947802da8..69f919454a4565 100644
--- a/remote-curl.c
+++ b/remote-curl.c
@@ -894,14 +894,6 @@ static int probe_rpc(struct rpc_state *rpc, struct slot_results *results)
 	return err;
 }
 
-static curl_off_t xcurl_off_t(size_t len)
-{
-	uintmax_t size = len;
-	if (size > maximum_signed_value_of_type(curl_off_t))
-		die(_("cannot handle pushes this big"));
-	return (curl_off_t)size;
-}
-
 /*
  * If flush_received is true, do not attempt to read any more; just use what's
  * in rpc->buf.
@@ -999,7 +991,7 @@ static int post_rpc(struct rpc_state *rpc, int stateless_connect, int flush_rece
 		 * and we just need to send it.
 		 */
 		curl_easy_setopt(slot->curl, CURLOPT_POSTFIELDS, gzip_body);
-		curl_easy_setopt(slot->curl, CURLOPT_POSTFIELDSIZE_LARGE, xcurl_off_t(gzip_size));
+		curl_easy_setopt(slot->curl, CURLOPT_POSTFIELDSIZE_LARGE, cast_size_t_to_curl_off_t(gzip_size));
 
 	} else if (use_gzip && 1024 < rpc->len) {
 		/* The client backend isn't giving us compressed data so
@@ -1030,7 +1022,7 @@ static int post_rpc(struct rpc_state *rpc, int stateless_connect, int flush_rece
 
 		headers = curl_slist_append(headers, "Content-Encoding: gzip");
 		curl_easy_setopt(slot->curl, CURLOPT_POSTFIELDS, gzip_body);
-		curl_easy_setopt(slot->curl, CURLOPT_POSTFIELDSIZE_LARGE, xcurl_off_t(gzip_size));
+		curl_easy_setopt(slot->curl, CURLOPT_POSTFIELDSIZE_LARGE, cast_size_t_to_curl_off_t(gzip_size));
 
 		if (options.verbosity > 1) {
 			fprintf(stderr, "POST %s (gzip %lu to %lu bytes)\n",
@@ -1043,7 +1035,7 @@ static int post_rpc(struct rpc_state *rpc, int stateless_connect, int flush_rece
 		 * more normal Content-Length approach.
 		 */
 		curl_easy_setopt(slot->curl, CURLOPT_POSTFIELDS, rpc->buf);
-		curl_easy_setopt(slot->curl, CURLOPT_POSTFIELDSIZE_LARGE, xcurl_off_t(rpc->len));
+		curl_easy_setopt(slot->curl, CURLOPT_POSTFIELDSIZE_LARGE, cast_size_t_to_curl_off_t(rpc->len));
 		if (options.verbosity > 1) {
 			fprintf(stderr, "POST %s (%lu bytes)\n",
 				rpc->service_name, (unsigned long)rpc->len);