diff --git a/source/graphics/Color.cpp b/source/graphics/Color.cpp
index 221844c630..f8dc267b3a 100644
--- a/source/graphics/Color.cpp
+++ b/source/graphics/Color.cpp
@@ -13,7 +13,7 @@
 #include "maths/MathUtil.h"
 #include "graphics/SColor.h"
 
-#if ARCH_IA32 || ARCH_AMD64
+#if ARCH_X86_X64
 # include <xmmintrin.h>
 # include "lib/sysdep/arch/x86_x64/x86_x64.h"
 #endif
@@ -33,7 +33,7 @@ SColor4ub (*ConvertRGBColorTo4ub)(const RGBColor& src) = fallback_ConvertRGBColo
 
 
 // Assembler-optimized function for color conversion
-#if ARCH_IA32 || ARCH_AMD64
+#if ARCH_X86_X64
 static SColor4ub sse_ConvertRGBColorTo4ub(const RGBColor& src)
 {
 	const __m128 zero = _mm_setzero_ps();
@@ -69,7 +69,7 @@ void ColorActivateFastImpl()
 	if(0)
 	{
 	}
-#if ARCH_IA32 || ARCH_AMD64
+#if ARCH_X86_X64
 	else if (x86_x64_cap(X86_X64_CAP_SSE))
 	{
 		ConvertRGBColorTo4ub = sse_ConvertRGBColorTo4ub;
diff --git a/source/lib/sysdep/arch.h b/source/lib/sysdep/arch.h
index 052e2bcf42..d206e2ea80 100644
--- a/source/lib/sysdep/arch.h
+++ b/source/lib/sysdep/arch.h
@@ -49,6 +49,12 @@
 # define ARCH_MIPS 0
 #endif
 
+// ensure exactly one architecture has been detected
+#if (ARCH_IA32+ARCH_IA64+ARCH_AMD64+ARCH_ALPHA+ARCH_ARM+ARCH_MIPS) != 1
+# error "architecture not correctly detected (either none or multiple ARCH_* defined)"
+#endif
+
+// "X86_X64"-specific code requires either IA-32 or AMD64
 #define ARCH_X86_X64 (ARCH_IA32|ARCH_AMD64)
 
 #endif	// #ifndef INCLUDED_ARCH
diff --git a/source/lib/sysdep/arch/x86_x64/x86_x64.h b/source/lib/sysdep/arch/x86_x64/x86_x64.h
index 87159e5c21..de8c146f2a 100644
--- a/source/lib/sysdep/arch/x86_x64/x86_x64.h
+++ b/source/lib/sysdep/arch/x86_x64/x86_x64.h
@@ -11,8 +11,8 @@
 #ifndef INCLUDED_X86_X64
 #define INCLUDED_X86_X64
 
-#if !ARCH_IA32 && !ARCH_AMD64
-#error "including x86_x64.h without ARCH_IA32=1 or ARCH_AMD64=1"
+#if !ARCH_X86_X64
+#error "including x86_x64.h without ARCH_X86_X64=1"
 #endif
 
 /**
diff --git a/source/lib/sysdep/os/win/wdbg_sym.cpp b/source/lib/sysdep/os/win/wdbg_sym.cpp
index aee8f8e5f0..7f80f9de2e 100644
--- a/source/lib/sysdep/os/win/wdbg_sym.cpp
+++ b/source/lib/sysdep/os/win/wdbg_sym.cpp
@@ -312,7 +312,7 @@ LibError wdbg_sym_WalkStack(StackFrameCallback cb, uintptr_t cbData, const CONTE
 		// this MUST be done inline and not in an external function because
 		// compiler-generated prolog code trashes some registers.
 
-#if ARCH_IA32 && !ARCH_AMD64
+#if ARCH_IA32
 		ia32_asm_GetCurrentContext(&context);
 #else
 		if(!s_RtlCaptureContext)
diff --git a/source/lib/sysdep/os/win/whrt/tsc.cpp b/source/lib/sysdep/os/win/whrt/tsc.cpp
index 0f89054ed5..4970d0a99b 100644
--- a/source/lib/sysdep/os/win/whrt/tsc.cpp
+++ b/source/lib/sysdep/os/win/whrt/tsc.cpp
@@ -18,7 +18,7 @@
 #include "lib/sysdep/os/win/win.h"
 #include "lib/sysdep/os/win/wutil.h"
 
-#if ARCH_IA32 || ARCH_AMD64
+#if ARCH_X86_X64
 # include "lib/sysdep/arch/x86_x64/x86_x64.h"	// x86_x64_rdtsc
 # include "lib/sysdep/arch/x86_x64/topology.h"
 #endif
@@ -36,7 +36,7 @@ enum AmdPowerNowFlags
 
 static bool IsThrottlingPossible()
 {
-#if ARCH_IA32 || ARCH_AMD64
+#if ARCH_X86_X64
 	x86_x64_CpuidRegs regs;
 	switch(x86_x64_Vendor())
 	{
@@ -71,7 +71,7 @@ public:
 		
 	LibError Activate()
 	{
-#if ARCH_IA32 || ARCH_AMD64
+#if ARCH_X86_X64
 		if(!x86_x64_cap(X86_X64_CAP_TSC))
 			return ERR::NO_SYS;		// NOWARN (CPU doesn't support RDTSC)
 #endif
@@ -114,7 +114,7 @@ public:
 				return false;
 		}
 
-#if ARCH_IA32 || ARCH_AMD64
+#if ARCH_X86_X64
 		// recent CPU:
 		if(x86_x64_Generation() >= 7)
 		{
diff --git a/source/lib/timer.cpp b/source/lib/timer.cpp
index 215e5c27ff..4420402513 100644
--- a/source/lib/timer.cpp
+++ b/source/lib/timer.cpp
@@ -25,7 +25,7 @@
 # include <unistd.h>
 #endif
 #include "lib/config2.h"	// CONFIG2_TIMER_ALLOW_RDTSC
-#if (ARCH_IA32 || ARCH_AMD64) && CONFIG2_TIMER_ALLOW_RDTSC
+#if ARCH_X86_X64 && CONFIG2_TIMER_ALLOW_RDTSC
 # include "lib/sysdep/arch/x86_x64/x86_x64.h"	// x86_x64_rdtsc
 #endif