diff --git a/src/Php/Optimizer/SsaTypeOptimizer.php b/src/Php/Optimizer/SsaTypeOptimizer.php
index ba8a6eb2..2cbd3f33 100644
--- a/src/Php/Optimizer/SsaTypeOptimizer.php
+++ b/src/Php/Optimizer/SsaTypeOptimizer.php
@@ -48,6 +48,7 @@ trait SsaTypeOptimizer
         }
 
         foreach ($groups as $varName => $varList) {
+            $varName = $this->escapeVarName($varName);
             // Skip parameters — they already have declared types
             if (isset($this->context->arguments[$varName])) {
                 continue;