diff --git a/format.cc b/format.cc
index b04045d2..b27a8a83 100644
--- a/format.cc
+++ b/format.cc
@@ -196,7 +196,10 @@ void fmt::Formatter::FormatDouble(
   case 0:
     type = 'g';
     break;
-  case 'e': case 'E': case 'f': case 'F': case 'g': case 'G':
+  case 'e': case 'E': case 'f': case 'g': case 'G':
+    break;
+  case 'F':
+    type = 'f';
     break;
   default:
     ReportUnknownType(type, "double");
diff --git a/format_test.cc b/format_test.cc
index 232371bd..93bb3e7f 100644
--- a/format_test.cc
+++ b/format_test.cc
@@ -480,8 +480,11 @@ TEST(FormatterTest, FormatDouble) {
   EXPECT_EQ("392.65", str(Format("{0:G}") << 392.65));
   EXPECT_EQ("392.650000", str(Format("{0:f}") << 392.65));
   EXPECT_EQ("392.650000", str(Format("{0:F}") << 392.65));
-  EXPECT_EQ("3.926500e+02", str(Format("{0:e}") << 392.65));
-  EXPECT_EQ("3.926500E+02", str(Format("{0:E}") << 392.65));
+  char buffer[256];
+  sprintf(buffer, "%e", 392.65);
+  EXPECT_EQ(buffer, str(Format("{0:e}") << 392.65));
+  sprintf(buffer, "%E", 392.65);
+  EXPECT_EQ(buffer, str(Format("{0:E}") << 392.65));
   EXPECT_EQ("+0000392.6", str(Format("{0:+010.4g}") << 392.65));
 }
 
@@ -493,8 +496,10 @@ TEST(FormatterTest, FormatLongDouble) {
   EXPECT_EQ("392.65", str(Format("{0:G}") << 392.65l));
   EXPECT_EQ("392.650000", str(Format("{0:f}") << 392.65l));
   EXPECT_EQ("392.650000", str(Format("{0:F}") << 392.65l));
-  EXPECT_EQ("3.926500e+02", str(Format("{0:e}") << 392.65l));
-  EXPECT_EQ("3.926500E+02", str(Format("{0:E}") << 392.65l));
+  char buffer[256];
+  sprintf(buffer, "%Le", 392.65);
+  EXPECT_EQ(buffer, str(Format("{0:e}") << 392.65));
+  sprintf(buffer, "%LE", 392.65);
   EXPECT_EQ("+0000392.6", str(Format("{0:+010.4g}") << 392.65l));
 }