diff --git a/test/format-test.cc b/test/format-test.cc
index 84dd725e..d69fce55 100644
--- a/test/format-test.cc
+++ b/test/format-test.cc
@@ -374,10 +374,14 @@ TEST(WriterTest, WriteLongLong) {
 TEST(WriterTest, WriteDouble) {
   CHECK_WRITE(4.2);
   CHECK_WRITE(-4.2);
+  CHECK_WRITE(std::numeric_limits<double>::min());
+  CHECK_WRITE(std::numeric_limits<double>::max());
 }
 
 TEST(WriterTest, WriteLongDouble) {
   CHECK_WRITE(4.2l);
+  CHECK_WRITE(-4.2l);
+  CHECK_WRITE(std::numeric_limits<long double>::min());
   CHECK_WRITE(std::numeric_limits<long double>::max());
 }
 
diff --git a/test/printf-test.cc b/test/printf-test.cc
index adf8d927..dfb022b7 100644
--- a/test/printf-test.cc
+++ b/test/printf-test.cc
@@ -362,7 +362,11 @@ TEST(PrintfTest, Length) {
   TestLength<intmax_t>("j");
   TestLength<std::size_t>("z");
   TestLength<std::ptrdiff_t>("t");
-  // TODO: test 'L' & 'll'
+  long double max = std::numeric_limits<long double>::max();
+  EXPECT_PRINTF(fmt::format("{}", max), "%g", max);
+  EXPECT_PRINTF(fmt::format("{}", max), "%Lg", max);
+  EXPECT_GT(sizeof(fmt::LongLong), sizeof(int));
+  // TODO: test 'L'
 }
 
 // TODO: test type specifier