diff --git a/tests/test-qemu-opts.c b/tests/test-qemu-opts.c
index 310485bb2e..8b92f7b0dc 100644
--- a/tests/test-qemu-opts.c
+++ b/tests/test-qemu-opts.c
@@ -603,17 +603,15 @@ static void test_opts_parse_number(void)
 
     /* Above upper limit */
     opts = qemu_opts_parse(&opts_list_01, "number1=18446744073709551616",
-                           false, &error_abort);
-    /* BUG: should reject */
-    g_assert_cmpuint(opts_count(opts), ==, 1);
-    g_assert_cmpuint(qemu_opt_get_number(opts, "number1", 1), ==, UINT64_MAX);
+                           false, &err);
+    error_free_or_abort(&err);
+    g_assert(!opts);
 
     /* Below lower limit */
     opts = qemu_opts_parse(&opts_list_01, "number1=-18446744073709551616",
-                           false, &error_abort);
-    /* BUG: should reject */
-    g_assert_cmpuint(opts_count(opts), ==, 1);
-    g_assert_cmpuint(qemu_opt_get_number(opts, "number1", 1), ==, UINT64_MAX);
+                           false, &err);
+    error_free_or_abort(&err);
+    g_assert(!opts);
 
     /* Hex and octal */
     opts = qemu_opts_parse(&opts_list_01, "number1=0x2a,number2=052",
@@ -624,9 +622,8 @@ static void test_opts_parse_number(void)
 
     /* Invalid */
     opts = qemu_opts_parse(&opts_list_01, "number1=", false, &err);
-    /* BUG: should reject */
-    g_assert_cmpuint(opts_count(opts), ==, 1);
-    g_assert_cmpuint(qemu_opt_get_number(opts, "number1", 1), ==, 0);
+    error_free_or_abort(&err);
+    g_assert(!opts);
     opts = qemu_opts_parse(&opts_list_01, "number1=eins", false, &err);
     error_free_or_abort(&err);
     g_assert(!opts);
diff --git a/util/qemu-option.c b/util/qemu-option.c
index 9708668847..273d00d485 100644
--- a/util/qemu-option.c
+++ b/util/qemu-option.c
@@ -141,11 +141,16 @@ static void parse_option_bool(const char *name, const char *value, bool *ret,
 static void parse_option_number(const char *name, const char *value,
                                 uint64_t *ret, Error **errp)
 {
-    char *postfix;
     uint64_t number;
+    int err;
 
-    number = strtoull(value, &postfix, 0);
-    if (*postfix != '\0') {
+    err = qemu_strtou64(value, NULL, 0, &number);
+    if (err == -ERANGE) {
+        error_setg(errp, "Value '%s' is too large for parameter '%s'",
+                   value, name);
+        return;
+    }
+    if (err) {
         error_setg(errp, QERR_INVALID_PARAMETER_VALUE, name, "a number");
         return;
     }