diff --git a/NEWS b/NEWS
index fbbc21aab..76019fe50 100644
--- a/NEWS
+++ b/NEWS
@@ -94,6 +94,9 @@ Bug fixes
   BGZF::errcode field after calling bgzf_close() as it may no longer be valid.
   (PR #2035, #2042)
 
+* Speed up hts_parse_decimal() handling of oversized exponents
+  (PR #2045)
+
 Documentation updates
 ---------------------
 
diff --git a/hts.c b/hts.c
index 571969cec..e8d9d91e6 100644
--- a/hts.c
+++ b/hts.c
@@ -3923,8 +3923,8 @@ long long hts_parse_decimal(const char *str, char **strend, int flags)
     }
 
     e -= decimals;
-    while (e > 0) n *= 10, e--;
-    while (e < 0) lost += n % 10, n /= 10, e++;
+    while (e > 0 && n) n *= 10, e--;
+    while (e < 0 && n) lost += n % 10, n /= 10, e++;
 
     if (lost > 0) {
         hts_log_warning("Discarding fractional part of %.*s", (int)(s - str), str);