diff --git a/CMakeLists.txt b/CMakeLists.txt
index cdcf2070e..dbaa5921e 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -120,11 +120,15 @@ foreach(dir ${DIRLIST})
 endforeach()
 
 # Detect CPU type and word size
-if(CMAKE_OSX_ARCHITECTURES MATCHES "ppc")
-	set(CMAKE_SYSTEM_PROCESSOR ppc)
-endif()
 math(EXPR BITS "${CMAKE_SIZEOF_VOID_P} * 8")
 string(TOLOWER ${CMAKE_SYSTEM_PROCESSOR} CMAKE_SYSTEM_PROCESSOR_LC)
+set(COUNT 1)
+foreach(ARCH ${CMAKE_OSX_ARCHITECTURES})
+	if(COUNT GREATER 1)
+		message(FATAL_ERROR "TurboVNC contains JNI code, so it cannot be built with multiple values in CMAKE_OSX_ARCHITECTURES.")
+	endif()
+	math(EXPR COUNT "${COUNT}+1")
+endforeach()
 if(CMAKE_SYSTEM_PROCESSOR_LC MATCHES "x86_64" OR
 	CMAKE_SYSTEM_PROCESSOR_LC MATCHES "amd64" OR
 	CMAKE_SYSTEM_PROCESSOR_LC MATCHES "i[0-9]86" OR
@@ -151,6 +155,12 @@ elseif(CMAKE_SYSTEM_PROCESSOR STREQUAL "ppc64" AND BITS EQUAL 32)
 else()
 	set(CPU_TYPE ${CMAKE_SYSTEM_PROCESSOR_LC})
 endif()
+if(CMAKE_OSX_ARCHITECTURES MATCHES "x86_64" OR
+	CMAKE_OSX_ARCHITECTURES MATCHES "arm64" OR
+	CMAKE_OSX_ARCHITECTURES MATCHES "i386" OR
+	CMAKE_OSX_ARCHITECTURES MATCHES "ppc")
+	set(CPU_TYPE ${CMAKE_OSX_ARCHITECTURES})
+endif()
 message(STATUS "${BITS}-bit build (${CPU_TYPE})")
 include(cmakescripts/FindTurboJPEG.cmake)