diff --git a/CHANGELOG.md b/CHANGELOG.md
index 1b2aa5c8b..c22d2ef91 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -2,6 +2,7 @@
 
 Bugfixes:
 * Improved uptime detection on SunOS via kstat. (#2674, Uptime, SunOS)
+* Fixed substring formatting returning the remaining string when a negative end index is before the start of the string. (General)
 
 # 2.70.0
 
diff --git a/src/common/impl/format.c b/src/common/impl/format.c
index b3b8ab190..6a9aa8c53 100644
--- a/src/common/impl/format.c
+++ b/src/common/impl/format.c
@@ -552,7 +552,7 @@ static bool parseFormatString(FFstrbuf* buffer, const FFstrbuf* formatstr, uint3
                         if (end < 0) {
                             end = (int32_t) tempString.length + end;
                         }
-                        if ((uint32_t) end > tempString.length) {
+                        if (end >= 0 && (uint32_t) end > tempString.length) {
                             end = (int32_t) tempString.length;
                         }
                         if (end > start) {
diff --git a/tests/format.c b/tests/format.c
index 374fd48df..0858c967b 100644
--- a/tests/format.c
+++ b/tests/format.c
@@ -96,6 +96,7 @@ int main(void) {
         VERIFY("output({1~10,10})", "12345 67890", "output()");
         VERIFY("output({1~10,5})", "12345 67890", "output()");
         VERIFY("output({1~3,-3})", "12345 67890", "output(45 67)");
+        VERIFY("output({1~0,-12})", "12345 67890", "output()");
         VERIFY("output({1~-5,-3})", "12345 67890", "output(67)");
         VERIFY("output({1~-0,10})", "12345 67890", "output(12345 6789)");
         VERIFY("output({1~-3,-5})", "12345 67890", "output()");