diff --git a/pyperformance/_benchmark.py b/pyperformance/_benchmark.py
index cd51dfe6..516fbbd1 100644
--- a/pyperformance/_benchmark.py
+++ b/pyperformance/_benchmark.py
@@ -252,7 +252,7 @@ def _resolve_restricted_opts(opts):
         if opt.startswith(FLAG + '='):
             idx = i + 1
             resolved.append(FLAG)
-            resolved.append(opt.partition('=')[-2])
+            resolved.append(opt.partition('=')[-1])
             resolved.extend(opts[idx:])
             break
         elif opt == FLAG: