diff --git a/LEGO1/omni/include/mxstring.h b/LEGO1/omni/include/mxstring.h
index 3c268839..5d973e69 100644
--- a/LEGO1/omni/include/mxstring.h
+++ b/LEGO1/omni/include/mxstring.h
@@ -20,8 +20,8 @@ class MxString : public MxCore {
 
 	MxString& operator=(const MxString& p_str);
 	const MxString& operator=(const char* p_str);
-	const MxString operator+(const MxString& p_str);
-	const MxString operator+(const char* p_str);
+	MxString operator+(const MxString& p_str) const;
+	MxString operator+(const char* p_str) const;
 	MxString& operator+=(const char* p_str);
 
 	static void CharSwap(char* p_a, char* p_b);
diff --git a/LEGO1/omni/src/common/mxstring.cpp b/LEGO1/omni/src/common/mxstring.cpp
index 07e77514..b33a7f10 100644
--- a/LEGO1/omni/src/common/mxstring.cpp
+++ b/LEGO1/omni/src/common/mxstring.cpp
@@ -128,7 +128,7 @@ const MxString& MxString::operator=(const char* p_str)
 }
 
 // FUNCTION: BETA10 0x1012c68a
-const MxString MxString::operator+(const MxString& p_str)
+MxString MxString::operator+(const MxString& p_str) const
 {
 	MxString tmp;
 	delete[] tmp.m_data;
@@ -146,7 +146,7 @@ const MxString MxString::operator+(const MxString& p_str)
 // This forces MSVC to add $ReturnUdt$ to the stack for 100% match.
 // FUNCTION: LEGO1 0x100ae580
 // FUNCTION: BETA10 0x1012c78d
-const MxString MxString::operator+(const char* p_str)
+MxString MxString::operator+(const char* p_str) const
 {
 	// MxString constructor allocates 1 byte for m_data, so free that first
 	MxString tmp;