diff --git a/tests/basictest.cpp b/tests/basictest.cpp
index b234689..6e82398 100644
--- a/tests/basictest.cpp
+++ b/tests/basictest.cpp
@@ -110,6 +110,7 @@ int main() {
 
 
   std::cout << "======= 64 bits " << std::endl;
+  Assert(basic_test_64bit("1.0000000000000006661338147750939242541790008544921875",1.0000000000000007));
   Assert(basic_test_64bit("1090544144181609348835077142190",0x1.b8779f2474dfbp+99));
   Assert(basic_test_64bit("2.2250738585072013e-308",2.2250738585072013e-308));
   Assert(basic_test_64bit("-92666518056446206563E3", -92666518056446206563E3));