diff --git a/qtest.c b/qtest.c
index da4826c..4c94708 100644
--- a/qtest.c
+++ b/qtest.c
@@ -27,6 +27,7 @@
 #include "qemu/config-file.h"
 #include "qemu/option.h"
 #include "qemu/error-report.h"
+#include "qemu/cutils.h"
 
 #define MAX_IRQ 256
 
@@ -324,12 +325,13 @@ static void qtest_process_command(CharDriverState *chr, gchar **words)
     } else if (strcmp(words[0], "outb") == 0 ||
                strcmp(words[0], "outw") == 0 ||
                strcmp(words[0], "outl") == 0) {
-        uint16_t addr;
-        uint32_t value;
+        unsigned long addr;
+        unsigned long value;
 
         g_assert(words[1] && words[2]);
-        addr = strtoul(words[1], NULL, 0);
-        value = strtoul(words[2], NULL, 0);
+        g_assert(qemu_strtoul(words[1], NULL, 0, &addr) == 0);
+        g_assert(qemu_strtoul(words[2], NULL, 0, &value) == 0);
+        g_assert(addr <= 0xffff);
 
         if (words[0][3] == 'b') {
             cpu_outb(addr, value);
@@ -343,11 +345,12 @@ static void qtest_process_command(CharDriverState *chr, gchar **words)
     } else if (strcmp(words[0], "inb") == 0 ||
         strcmp(words[0], "inw") == 0 ||
         strcmp(words[0], "inl") == 0) {
-        uint16_t addr;
+        unsigned long addr;
         uint32_t value = -1U;
 
         g_assert(words[1]);
-        addr = strtoul(words[1], NULL, 0);
+        g_assert(qemu_strtoul(words[1], NULL, 0, &addr) == 0);
+        g_assert(addr <= 0xffff);
 
         if (words[0][2] == 'b') {
             value = cpu_inb(addr);
@@ -366,8 +369,8 @@ static void qtest_process_command(CharDriverState *chr, gchar **words)
         uint64_t value;
 
         g_assert(words[1] && words[2]);
-        addr = strtoull(words[1], NULL, 0);
-        value = strtoull(words[2], NULL, 0);
+        g_assert(qemu_strtoull(words[1], NULL, 0, &addr) == 0);
+        g_assert(qemu_strtoull(words[2], NULL, 0, &value) == 0);
 
         if (words[0][5] == 'b') {
             uint8_t data = value;
@@ -395,7 +398,7 @@ static void qtest_process_command(CharDriverState *chr, gchar **words)
         uint64_t value = UINT64_C(-1);
 
         g_assert(words[1]);
-        addr = strtoull(words[1], NULL, 0);
+        g_assert(qemu_strtoull(words[1], NULL, 0, &addr) == 0);
 
         if (words[0][4] == 'b') {
             uint8_t data;
@@ -421,8 +424,8 @@ static void qtest_process_command(CharDriverState *chr, gchar **words)
         char *enc;
 
         g_assert(words[1] && words[2]);
-        addr = strtoull(words[1], NULL, 0);
-        len = strtoull(words[2], NULL, 0);
+        g_assert(qemu_strtoull(words[1], NULL, 0, &addr) == 0);
+        g_assert(qemu_strtoull(words[2], NULL, 0, &len) == 0);
 
         data = g_malloc(len);
         cpu_physical_memory_read(addr, data, len);
@@ -443,8 +446,8 @@ static void qtest_process_command(CharDriverState *chr, gchar **words)
         gchar *b64_data;
 
         g_assert(words[1] && words[2]);
-        addr = strtoull(words[1], NULL, 0);
-        len = strtoull(words[2], NULL, 0);
+        g_assert(qemu_strtoull(words[1], NULL, 0, &addr) == 0);
+        g_assert(qemu_strtoull(words[2], NULL, 0, &len) == 0);
 
         data = g_malloc(len);
         cpu_physical_memory_read(addr, data, len);
@@ -460,8 +463,8 @@ static void qtest_process_command(CharDriverState *chr, gchar **words)
         size_t data_len;
 
         g_assert(words[1] && words[2] && words[3]);
-        addr = strtoull(words[1], NULL, 0);
-        len = strtoull(words[2], NULL, 0);
+        g_assert(qemu_strtoull(words[1], NULL, 0, &addr) == 0);
+        g_assert(qemu_strtoull(words[2], NULL, 0, &len) == 0);
 
         data_len = strlen(words[3]);
         if (data_len < 3) {
@@ -486,12 +489,12 @@ static void qtest_process_command(CharDriverState *chr, gchar **words)
     } else if (strcmp(words[0], "memset") == 0) {
         uint64_t addr, len;
         uint8_t *data;
-        uint8_t pattern;
+        unsigned long pattern;
 
         g_assert(words[1] && words[2] && words[3]);
-        addr = strtoull(words[1], NULL, 0);
-        len = strtoull(words[2], NULL, 0);
-        pattern = strtoull(words[3], NULL, 0);
+        g_assert(qemu_strtoull(words[1], NULL, 0, &addr) == 0);
+        g_assert(qemu_strtoull(words[2], NULL, 0, &len) == 0);
+        g_assert(qemu_strtoul(words[3], NULL, 0, &pattern) == 0);
 
         data = g_malloc(len);
         memset(data, pattern, len);
@@ -507,8 +510,8 @@ static void qtest_process_command(CharDriverState *chr, gchar **words)
         gsize out_len;
 
         g_assert(words[1] && words[2] && words[3]);
-        addr = strtoull(words[1], NULL, 0);
-        len = strtoull(words[2], NULL, 0);
+        g_assert(qemu_strtoull(words[1], NULL, 0, &addr) == 0);
+        g_assert(qemu_strtoull(words[2], NULL, 0, &len) == 0);
 
         data_len = strlen(words[3]);
         if (data_len < 3) {
@@ -532,7 +535,7 @@ static void qtest_process_command(CharDriverState *chr, gchar **words)
         int64_t ns;
 
         if (words[1]) {
-            ns = strtoll(words[1], NULL, 0);
+            g_assert(qemu_strtoll(words[1], NULL, 0, &ns) == 0);
         } else {
             ns = qemu_clock_deadline_ns_all(QEMU_CLOCK_VIRTUAL);
         }
@@ -544,7 +547,7 @@ static void qtest_process_command(CharDriverState *chr, gchar **words)
         int64_t ns;
 
         g_assert(words[1]);
-        ns = strtoll(words[1], NULL, 0);
+        g_assert(qemu_strtoll(words[1], NULL, 0, &ns) == 0);
         qtest_clock_warp(ns);
         qtest_send_prefix(chr);
         qtest_sendf(chr, "OK %"PRIi64"\n",
