diff --git a/functions.go b/functions.go
index db5f2e1..f5d336b 100644
--- a/functions.go
+++ b/functions.go
@@ -22,13 +22,17 @@ import (
 // GoFunction defines the signature for Go functions callable from Lua
 type GoFunction func(*State) int
 
+// Static registry size reduces resizing operations
+const initialRegistrySize = 64
+
 var (
 	// functionRegistry stores all registered Go functions
 	functionRegistry = struct {
 		sync.RWMutex
-		funcs map[unsafe.Pointer]GoFunction
+		funcs    map[unsafe.Pointer]GoFunction
+		initOnce sync.Once
 	}{
-		funcs: make(map[unsafe.Pointer]GoFunction),
+		funcs: make(map[unsafe.Pointer]GoFunction, initialRegistrySize),
 	}
 )
 
@@ -43,6 +47,7 @@ func goFunctionWrapper(L *C.lua_State) C.int {
 		return -1
 	}
 
+	// Use read-lock for better concurrency
 	functionRegistry.RLock()
 	fn, ok := functionRegistry.funcs[ptr]
 	functionRegistry.RUnlock()