diff --git a/configure.ac b/configure.ac
index 332fb83b..e4e6b526 100644
--- a/configure.ac
+++ b/configure.ac
@@ -1,4 +1,4 @@
-AC_INIT([yara], [4.1.0], [vmalvarez@virustotal.com])
+AC_INIT([yara], [4.1.1], [vmalvarez@virustotal.com])
 
 AM_SILENT_RULES([yes])
 AC_CONFIG_SRCDIR([cli/yara.c])
@@ -121,6 +121,14 @@ AC_ARG_ENABLE([profiling],
     CFLAGS="$CFLAGS -DYR_PROFILING_ENABLED"
   fi])
 
+AC_ARG_WITH([debug-verbose],
+  [AS_HELP_STRING([--with-debug-verbose=[[NUM]]], [Turn on runtime debugging information])],
+  [if test $withval -gt 0; then
+    AC_DEFINE_UNQUOTED([YR_DEBUG_VERBOSITY], [$withval])
+   else
+    AC_MSG_ERROR([debug verbosity must be greater than 0])
+  fi])
+
 AC_ARG_ENABLE([cuckoo],
   [AS_HELP_STRING([--enable-cuckoo], [enable cuckoo module])],
   [if test x$enableval = xyes; then
diff --git a/libyara/scan.c b/libyara/scan.c
index e4728bb0..41ecb162 100644
--- a/libyara/scan.c
+++ b/libyara/scan.c
@@ -635,7 +635,7 @@ static int _yr_scan_match_callback(
       2,
       stderr,
       "+ %s(match_data=%p match_length=%d) { //"
-      " match_offset=%" PRId64 " args->data=%p args->string.length=%u"
+      " match_offset=%zu args->data=%p args->string.length=%u"
       " args->data_base=0x%" PRIx64 " args->data_size=%zu"
       " args->forward_matches=%'u\n",
       __FUNCTION__,