diff --git a/src/arch/x86/lib/cpu.c b/src/arch/x86/lib/cpu.c
index ada57e22fe..8aacaac196 100644
--- a/src/arch/x86/lib/cpu.c
+++ b/src/arch/x86/lib/cpu.c
@@ -147,7 +147,7 @@ int cpu_phys_address_size(void)
 	if (cpu_cpuid_extended_level() >= 0x80000008)
 		return cpuid_eax(0x80000008) & 0xff;
 
-	if (cpuid_eax(1) & (CPUID_FEATURE_PAE | CPUID_FEATURE_PSE36))
+	if (cpuid_edx(1) & (CPUID_FEATURE_PAE | CPUID_FEATURE_PSE36))
 		return 36;
 	return 32;
 }