diff --git a/fast-import.c b/fast-import.c
index 5e89eef1aa9884605c600f9b9add32207ec41f43..45b4edf36b04970ccb5589e9abf93d8382c6da9b 100644
--- a/fast-import.c
+++ b/fast-import.c
@@ -1541,9 +1541,10 @@ static void dump_marks(void)
 
 	f = fdopen(mark_fd, "w");
 	if (!f) {
+		int saved_errno = errno;
 		rollback_lock_file(&mark_lock);
 		failure |= error("Unable to write marks file %s: %s",
-			mark_file, strerror(errno));
+			mark_file, strerror(saved_errno));
 		return;
 	}
 
@@ -1556,16 +1557,18 @@ static void dump_marks(void)
 
 	dump_marks_helper(f, 0, marks);
 	if (ferror(f) || fclose(f)) {
+		int saved_errno = errno;
 		rollback_lock_file(&mark_lock);
 		failure |= error("Unable to write marks file %s: %s",
-			mark_file, strerror(errno));
+			mark_file, strerror(saved_errno));
 		return;
 	}
 
 	if (commit_lock_file(&mark_lock)) {
+		int saved_errno = errno;
 		rollback_lock_file(&mark_lock);
 		failure |= error("Unable to commit marks file %s: %s",
-			mark_file, strerror(errno));
+			mark_file, strerror(saved_errno));
 		return;
 	}
 }