1 files changed, 3 insertions, 3 deletions

diff --git a/src/lib_string.c b/src/lib_string.c
index 3dac9d37..89ec4f25 100644
--- a/src/lib_string.c
+++ b/src/lib_string.c
@@ -780,20 +780,20 @@ LJLIB_CF(string_format)
         addintlen(form);
         sprintf(buff, form, num2uintfrm(L, arg));
         break;
-      case 'e':  case 'E': case 'f': case 'g': case 'G': {
+      case 'e':  case 'E': case 'f': case 'g': case 'G': case 'a': case 'A': {
         TValue tv;
         tv.n = lj_lib_checknum(L, arg);
         if (LJ_UNLIKELY((tv.u32.hi << 1) >= 0xffe00000)) {
           /* Canonicalize output of non-finite values. */
           char *p, nbuf[LJ_STR_NUMBUF];
           size_t len = lj_str_bufnum(nbuf, &tv);
-          if (strfrmt[-1] == 'E' || strfrmt[-1] == 'G') {
+          if (strfrmt[-1] < 'a') {
             nbuf[len-3] = nbuf[len-3] - 0x20;
             nbuf[len-2] = nbuf[len-2] - 0x20;
             nbuf[len-1] = nbuf[len-1] - 0x20;
           }
           nbuf[len] = '\0';
-          for (p = form; *p < 'e' && *p != '.'; p++) ;
+          for (p = form; *p < 'A' && *p != '.'; p++) ;
           *p++ = 's'; *p = '\0';
           sprintf(buff, form, nbuf);
           break;