diff --git a/configure.ac b/configure.ac
index 7859991..41d4442 100644
--- a/configure.ac
+++ b/configure.ac
@@ -1,7 +1,7 @@
 AC_INIT([libcpuid CPU Identification library], [0.1.3], [libcpuid-devel@lists.sourceforge.net], [libcpuid])
 AC_CONFIG_SRCDIR([libcpuid/libcpuid.h])
-AC_CONFIG_HEADERS([config.h])
-AM_INIT_AUTOMAKE([-Wall dist-bzip2 dist-zip foreign])
+AM_CONFIG_HEADER([config.h])
+AM_INIT_AUTOMAKE([dist-bzip2 dist-zip foreign])
 
 dnl Versioning scheme shamelessly copied from libexif.
 dnl Short walkthrough. C means CURRENT, A mean AGE, R means REVISION
diff --git a/libcpuid/rdtsc.c b/libcpuid/rdtsc.c
index 46eb26b..a7bbd0c 100644
--- a/libcpuid/rdtsc.c
+++ b/libcpuid/rdtsc.c
@@ -278,7 +278,7 @@ int cpu_clock_by_ic(int millis, int runs)
 		} while (t1 - t0 < tl * (uint64_t) 8);
 		// cpu_Hz = cycles_inner * cycles_outer * 256 / (t1 - t0) * 1000000
 		debugf(2, "c = %d, td = %llu\n", c, t1 - t0);
-		hz = ((uint64_t) cycles_inner * (uint64_t) 256 + 12) * 
+		hz = ((uint64_t) cycles_inner * (uint64_t) 258 + 12) * 
 		     (uint64_t) cycles_outer * (uint64_t) sse_multiplier * (uint64_t) c * (uint64_t) 1000000
 		     / (t1 - t0);
 		cur_value = (int) (hz / 1000000);