diff --git a/src/AST/MulNode.cpp b/src/AST/MulNode.cpp
index 3662540..9b6281f 100644
--- a/src/AST/MulNode.cpp
+++ b/src/AST/MulNode.cpp
@@ -20,5 +20,6 @@ llvm::Value* MulNode::codegen(IRBuilder* generator)
         return generator->getBuilder()->CreateSDiv(left->codegen(generator), right->codegen(generator));
     default:
         assert(0 && "unreachable");
+        return nullptr;
     }
 }
\ No newline at end of file
diff --git a/src/AST/SumNode.cpp b/src/AST/SumNode.cpp
index aa06956..39cc1e4 100644
--- a/src/AST/SumNode.cpp
+++ b/src/AST/SumNode.cpp
@@ -20,5 +20,6 @@ llvm::Value* SumNode::codegen(IRBuilder* generator)
         return generator->getBuilder()->CreateSub(left->codegen(generator), right->codegen(generator));
     default:
         assert(0 && "unreachable");
+        return nullptr;
     }
 }
\ No newline at end of file