diff --git a/src/driver/toks_driver_ctx.c b/src/driver/toks_driver_ctx.c
index 0567be9..d8ee050 100644
--- a/src/driver/toks_driver_ctx.c
+++ b/src/driver/toks_driver_ctx.c
@@ -90,6 +90,29 @@ static int toks_driver_usage(
 	return TOKS_USAGE;
 }
 
+static int64_t toks_arg_to_int64(struct argv_entry * entry)
+{
+	int64_t      ret;
+	const char * ch;
+
+	for (ret=0, ch=entry->arg; *ch && (ret>=0); ch++) {
+		if ((*ch < '0') || (*ch >'9'))
+			return (-1);
+
+		ret *= 10;
+		ret += (*ch - '0');
+	}
+
+	return ret;
+}
+
+static int32_t toks_arg_to_int32(struct argv_entry * entry)
+{
+	int64_t ret = toks_arg_to_int64(entry);
+	return (ret >= 0) && (ret <= 0x7fffffff)
+		? ret : (-1);
+}
+
 static int32_t toks_query_performance_counters_failover(nt_filetime * ticks)
 {
 	(void)ticks;
@@ -259,7 +282,6 @@ int toks_get_driver_ctx(
 	nt_guid				svcguid;
 	const char *			program;
 	const char *			refstr;
-	const char *			ch;
 	int				ntokens;
 	int32_t				tokpid;
 	int32_t				tsyspid;
@@ -337,46 +359,21 @@ int toks_get_driver_ctx(
 					break;
 
 				case TAG_PID:
-					pid = entry;
-
-					for (tokpid=0, ch=entry->arg; *ch && (tokpid>=0); ch++)
-						if ((*ch < '0') || (*ch >'9'))
-							tokpid = -1;
-						else
-							tokpid = tokpid * 10 + (*ch - '0');
+					tokpid = toks_arg_to_int32((pid=entry));
 					break;
 
 				case TAG_SYSPID:
-					syspid = entry;
-
-					for (tsyspid=0, ch=entry->arg; *ch && (tsyspid>=0); ch++)
-						if ((*ch < '0') || (*ch >'9'))
-							tsyspid = -1;
-						else
-							tsyspid = tsyspid * 10 + (*ch - '0');
+					tsyspid = toks_arg_to_int32((syspid=entry));
 					break;
 
 				case TAG_TIMEOUT:
-					msecs = entry;
-
-					for (timeout=0, ch=entry->arg; *ch && (timeout>=0); ch++)
-						if ((*ch < '0') || (*ch >'9'))
-							timeout = -2;
-						else if ((ch - entry->arg) > 15)
-							timeout = -2;
-						else
-							timeout = timeout * 10 + (*ch - '0');
-
+					timeout = toks_arg_to_int64((msecs=entry));
+					timeout = (timeout < 0) ? (-2) : timeout;
 					break;
 
 				case TAG_TOKENS:
-					for (ntokens=0, ch=entry->arg; *ch && (ntokens>=0); ch++)
-						if ((*ch < '0') || (*ch >'9'))
-							ntokens = -1;
-						else if (ntokens >= 1000)
-							ntokens = -1;
-						else
-							ntokens = ntokens * 10 + (*ch - '0');
+					ntokens = toks_arg_to_int32(entry);
+					ntokens = (ntokens > 9999) ? (-1) : ntokens;
 					break;
 
 				case TAG_CONNECT: