diff --git a/flang/runtime/edit-output.cpp b/flang/runtime/edit-output.cpp
--- a/flang/runtime/edit-output.cpp
+++ b/flang/runtime/edit-output.cpp
@@ -199,7 +199,7 @@
   }
   *--exponent = expo < 0 ? '-' : '+';
   if (edit.expoDigits || edit.IsListDirected() || exponent + 3 == eEnd) {
-    *--exponent = edit.descriptor == 'D' ? 'D' : 'E'; // not 'G'
+    *--exponent = edit.descriptor == 'D' ? 'D' : 'E'; // not 'G' or 'Q'
   }
   length = eEnd - exponent;
   return overflow ? nullptr : exponent;
@@ -264,9 +264,7 @@
   if (editWidth == 0) { // "the processor selects the field width"
     if (edit.digits.has_value()) { // E0.d
       if (editDigits == 0) { // E0.0
-        editWidth = 7; // -.0E+ee
-      } else {
-        editWidth = editDigits + 6; // -.666E+ee
+        significantDigits = 1;
       }
     } else { // E0
       flags |= decimal::Minimize;
@@ -485,7 +483,7 @@
   int significantDigits{
       edit.digits.value_or(BinaryFloatingPoint::decimalPrecision)}; // 'd'
   if (editWidth > 0 && significantDigits == 0) {
-    return edit; // Gw.0 -> Ew.0 for w > 0
+    return edit; // Gw.0Ee -> Ew.0Ee for w > 0
   }
   int flags{0};
   if (edit.modes.editingFlags & signPlus) {
@@ -498,7 +496,10 @@
   }
   int expo{IsZero() ? 1 : converted.decimalExponent}; // 's'
   if (expo < 0 || expo > significantDigits) {
-    return edit; // Ew.d
+    if (editWidth == 0 && !edit.expoDigits) { // G0.d -> G0.dE0
+      edit.expoDigits = 0;
+    }
+    return edit; // Ew.dEe
   }
   edit.descriptor = 'F';
   edit.modes.scale = 0; // kP is ignored for G when no exponent field
diff --git a/flang/unittests/Runtime/NumericalFormatTest.cpp b/flang/unittests/Runtime/NumericalFormatTest.cpp
--- a/flang/unittests/Runtime/NumericalFormatTest.cpp
+++ b/flang/unittests/Runtime/NumericalFormatTest.cpp
@@ -394,9 +394,9 @@
               {"(E62.55,';')",
                   " 0.1000000000000000055511151231257827021181583404541015625E+"
                   "00;"},
-              {"(E0.0,';')", "0.E+00;"},
+              {"(E0.0,';')", ".1E+00;"},
               {"(E0.55,';')",
-                  "0.1000000000000000055511151231257827021181583404541015625E+"
+                  ".1000000000000000055511151231257827021181583404541015625E+"
                   "00;"},
               {"(E0,';')", ".1E+00;"},
               {"(F58.55,';')",
@@ -491,7 +491,7 @@
                   "701797267771758512566055119913150489110145103786273816725095"
                   "583738973359899366480994116420570263709027924276754456522908"
                   "75386825064197182655334472656250-323;"},
-              {"(G0,';')", ".5-323;"},
+              {"(G0,';')", ".5E-323;"},
               {"(E757.750,';')",
                   " 0."
                   "494065645841246544176568792868221372365059802614324764425585"
@@ -586,7 +586,7 @@
                   "408698898317506783884692609277397797285865965494109136909540"
                   "61364675687023986783152906809846172109246253967285156250-"
                   "307;"},
-              {"(G0,';')", ".22250738585072014-307;"},
+              {"(G0,';')", ".22250738585072014E-307;"},
           }},
       {// greatest finite
           0x7fefffffffffffffuLL,
@@ -616,7 +616,7 @@
                   "090389328944075868508455133942304583236903222948165808559332"
                   "123348274797826204144723168738177180919299881250404026184124"
                   "8583680000+306;"},
-              {"(G0,';')", ".17976931348623157+309;"},
+              {"(G0,';')", ".17976931348623157E+309;"},
           }},
   };