diff --git a/src/mir/builder/if_form.rs b/src/mir/builder/if_form.rs
index 8e79f209..86f63495 100644
--- a/src/mir/builder/if_form.rs
+++ b/src/mir/builder/if_form.rs
@@ -123,7 +123,9 @@ impl MirBuilder {
                 }
             }
             let void_val = crate::mir::builder::emission::constant::emit_void(self);
-            (void_val, None, None)
+            // Phase 25.1c/k: Pass PHI-renamed variable_map for empty else branch
+            // This ensures merge_modified_vars uses correct ValueIds after PHI renaming
+            (void_val, None, Some(self.variable_map.clone()))
         };
         let else_exit_block = self.current_block()?;
         let else_reaches_merge = !self.is_current_block_terminated();