diff --git a/crates/compiler/builtins/bitcode/src/str.zig b/crates/compiler/builtins/bitcode/src/str.zig
index e6996d83a3..930fd26cf5 100644
--- a/crates/compiler/builtins/bitcode/src/str.zig
+++ b/crates/compiler/builtins/bitcode/src/str.zig
@@ -800,6 +800,12 @@ fn strSplitHelp(array: [*]RocStr, string: RocStr, delimiter: RocStr) void {
 
             while (delimiter_index < delimiter_len) {
                 var delimiterChar = delimiter_bytes_ptrs[delimiter_index];
+
+                if (str_index + delimiter_index >= str_len) {
+                    matches_delimiter = false;
+                    break;
+                }
+
                 var strChar = str_bytes[str_index + delimiter_index];
 
                 if (delimiterChar != strChar) {