diff --git a/crypto/x86cpuid.pl b/crypto/x86cpuid.pl
index a7464af19..201df9107 100644
--- a/crypto/x86cpuid.pl
+++ b/crypto/x86cpuid.pl
@@ -60,6 +60,7 @@ for (@ARGV) { $sse2=1 if (/-DOPENSSL_IA32_SSE2/); }
 	&inc	("esi");		# number of cores
 
 	&mov	("eax",1);
+	&xor	("ecx","ecx");
 	&cpuid	();
 	&bt	("edx",28);
 	&jnc	(&label("done"));
@@ -84,6 +85,7 @@ for (@ARGV) { $sse2=1 if (/-DOPENSSL_IA32_SSE2/); }
 
 &set_label("nocacheinfo");
 	&mov	("eax",1);
+	&xor	("ecx","ecx");
 	&cpuid	();
 	&cmp	("ebp",0);
 	&jne	(&label("notP4"));