--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -60,13 +60,13 @@
 if(CMAKE_SYSTEM_PROCESSOR MATCHES "^mips")
   set(PROCESSOR_IS_MIPS TRUE)
 elseif(CMAKE_SYSTEM_PROCESSOR MATCHES "^(aarch64|arm64)")
   set(PROCESSOR_IS_AARCH64 TRUE)
 elseif(CMAKE_SYSTEM_PROCESSOR MATCHES "^arm")
   set(PROCESSOR_IS_ARM TRUE)
-elseif(CMAKE_SYSTEM_PROCESSOR MATCHES "(x86_64)|(AMD64|amd64)|(^i.86$)")
+elseif(CMAKE_SYSTEM_PROCESSOR MATCHES "(x86)|(AMD64|amd64)|(^i.86$)")
   set(PROCESSOR_IS_X86 TRUE)
 elseif(CMAKE_SYSTEM_PROCESSOR MATCHES "^(powerpc|ppc)")
   set(PROCESSOR_IS_POWER TRUE)
 endif()
 
 macro(add_cpu_features_headers_and_sources HDRS_LIST_NAME SRCS_LIST_NAME)