diff --git a/src/Context/context.hpp b/src/Context/context.hpp
index d149eb2..92c0cdb 100644
--- a/src/Context/context.hpp
+++ b/src/Context/context.hpp
@@ -366,6 +366,7 @@ namespace Fig
             }
 
             assert(false);
+            return Function(); // ignore warning
         }
 
         const Function &getImplementedMethod(const TypeInfo &structType,
@@ -385,6 +386,7 @@ namespace Fig
                 return parent->getImplementedMethod(structType, functionName);
 
             assert(false); // not found
+            throw ""; // ignore warning
         }
 
         void printStackTrace(std::ostream &os = std::cerr, int indent = 0) const
diff --git a/src/Evaluator/evaluator.cpp b/src/Evaluator/evaluator.cpp
index 1e05514..79d1e87 100644
--- a/src/Evaluator/evaluator.cpp
+++ b/src/Evaluator/evaluator.cpp
@@ -984,6 +984,7 @@ namespace Fig
             }
 
             default: assert(false);
+            return Object::getNullInstance(); // ignore warning
         }
     }
     StatementResult Evaluator::evalBlockStatement(Ast::BlockStatement block, ContextPtr ctx)
diff --git a/src/Value/value.cpp b/src/Value/value.cpp
index 491e8db..110535c 100644
--- a/src/Value/value.cpp
+++ b/src/Value/value.cpp
@@ -76,6 +76,7 @@ namespace Fig
                 return std::hash<TypeInfo>{}(si.parentType) + std::hash<uint64_t>{}(reinterpret_cast<uint64_t>(std::addressof(*si.localContext)));
             }
             assert(false);
+            throw ""; // ignore warning
         }
     }
 
diff --git a/xmake.lua b/xmake.lua
index 61522ab..d910984 100644
--- a/xmake.lua
+++ b/xmake.lua
@@ -8,17 +8,20 @@ target("Fig")
     set_languages("c++23")
 
     if is_plat("linux") then
+        -- Linux: clang + libc++
         set_toolchains("clang")
         add_cxxflags("-stdlib=libc++")
         add_ldflags("-stdlib=libc++")
-    elseif is_plat("windows") then
-        set_toolchains("mingw")
-        add_cxxflags("-stdlib=libc++")
-        add_ldflags("-static")
     elseif is_plat("mingw") then
-        set_toolchains("mingw")
-        add_cxxflags("-static")
-        add_ldflags("-static")
+        -- 1. CI cross (Linux -> Windows)
+        -- 2. local dev (Windows + llvm-mingw)
+        set_toolchains("clang")
+        -- static lib
+        add_cxxflags("-target x86_64-w64-mingw32", "-static")
+        
+        -- add_ldflags("-target x86_64-w64-mingw32", "-static")
+        -- add_cxxflags("-stdlib=libc++")
+        -- add_ldflags("-stdlib=libc++")
     end
     
     add_ldflags("-Wl,--stack,268435456")