diff --git a/CMakeLists.txt b/CMakeLists.txt
index 4b226167..c44c8cae 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -50,8 +50,12 @@ option(BUILD_SERVER "Build server dll" ON)
 if(CMAKE_SIZEOF_VOID_P EQUAL 4 OR
 	((WIN32 OR ${CMAKE_SYSTEM_NAME} STREQUAL "Linux")
 	AND (CMAKE_SYSTEM_PROCESSOR STREQUAL "x64"
+	OR CMAKE_SYSTEM_PROCESSOR STREQUAL "X64"
 	OR CMAKE_SYSTEM_PROCESSOR STREQUAL "x86_64"
-	OR CMAKE_SYSTEM_PROCESSOR STREQUAL "amd64")))
+	OR CMAKE_SYSTEM_PROCESSOR STREQUAL "X86_64"
+	OR CMAKE_SYSTEM_PROCESSOR STREQUAL "amd64"
+	OR CMAKE_SYSTEM_PROCESSOR STREQUAL "AMD64"
+	OR CMAKE_SYSTEM_PROCESSOR STREQUAL "EM64T")))
 	option(64BIT "Disable auto -m32 appending to compiler flags" OFF)
 else()
 	option(64BIT "Disable auto -m32 appending to compiler flags" ON)
@@ -61,9 +65,14 @@ endif()
 # so may need to set options here manually.
 if((WIN32 OR ${CMAKE_SYSTEM_NAME} STREQUAL "Linux")
 	AND (((CMAKE_SYSTEM_PROCESSOR STREQUAL "x64"
+	OR CMAKE_SYSTEM_PROCESSOR STREQUAL "X64"
 	OR CMAKE_SYSTEM_PROCESSOR STREQUAL "x86_64"
-	OR CMAKE_SYSTEM_PROCESSOR STREQUAL "amd64") AND NOT 64BIT)
+	OR CMAKE_SYSTEM_PROCESSOR STREQUAL "X86_64"
+	OR CMAKE_SYSTEM_PROCESSOR STREQUAL "amd64"
+	OR CMAKE_SYSTEM_PROCESSOR STREQUAL "AMD64"
+	OR CMAKE_SYSTEM_PROCESSOR STREQUAL "EM64T") AND NOT 64BIT)
 	OR CMAKE_SYSTEM_PROCESSOR STREQUAL "x86"
+	OR CMAKE_SYSTEM_PROCESSOR STREQUAL "X86"
 	OR CMAKE_SYSTEM_PROCESSOR STREQUAL "i386"))
 	option(GOLDSOURCE_SUPPORT "Build goldsource compatible client library" ON)
 else()