diff --git a/README.chromium b/README.chromium
index cd771b0a0..752bc5d4b 100644
--- a/README.chromium
+++ b/README.chromium
@@ -1,6 +1,6 @@
 Name: libyuv
 URL: http://code.google.com/p/libyuv/
-Version: 620
+Version: 621
 License: BSD
 License File: LICENSE
 
diff --git a/include/libyuv/version.h b/include/libyuv/version.h
index 0af47939a..ab5216c27 100644
--- a/include/libyuv/version.h
+++ b/include/libyuv/version.h
@@ -11,6 +11,6 @@
 #ifndef INCLUDE_LIBYUV_VERSION_H_  // NOLINT
 #define INCLUDE_LIBYUV_VERSION_H_
 
-#define LIBYUV_VERSION 620
+#define LIBYUV_VERSION 621
 
 #endif  // INCLUDE_LIBYUV_VERSION_H_  NOLINT
diff --git a/util/psnr_main.cc b/util/psnr_main.cc
index 9bcb3762b..5d52e671a 100644
--- a/util/psnr_main.cc
+++ b/util/psnr_main.cc
@@ -57,7 +57,9 @@ int num_skip_org = 0;
 int num_skip_rec = 0;
 int num_frames = 0;
 int do_yscale = 0;
+#ifdef _OPENMP
 int num_threads = 0;
+#endif
 
 bool ExtractResolutionFromYuvFilename(const char *name,
                                       int* width_ptr,
@@ -115,7 +117,9 @@ void PrintHelp(const char * program) {
   printf(" -swap .................. Swap U and V plane\n");
   printf(" -skip <org> <rec> ...... Number of frame to skip of org and rec\n");
   printf(" -frames <num> .......... Number of frames to compare\n");
+#ifdef _OPENMP
   printf(" -t <num> ............... Number of threads\n");
+#endif
   printf(" -yscale ................ Scale org Y values of 16..240 to 0..255\n");
   printf(" -n ..................... Show file name\n");
   printf(" -v ..................... verbose++\n");
@@ -156,8 +160,10 @@ void ParseOptions(int argc, const char *argv[]) {
       num_skip_rec = atoi(argv[++c]);   // NOLINT
     } else if (!strcmp(argv[c], "-frames") && c + 1 < argc) {
       num_frames = atoi(argv[++c]);     // NOLINT
+#ifdef _OPENMP
     } else if (!strcmp(argv[c], "-t") && c + 1 < argc) {
       num_threads = atoi(argv[++c]);    // NOLINT
+#endif
     } else if (fileindex_org == 0) {
       fileindex_org = c;
     } else if (fileindex_rec == 0) {