diff --git a/tinymix.c b/tinymix.c
index afc2fee..7deac12 100644
--- a/tinymix.c
+++ b/tinymix.c
@@ -31,6 +31,8 @@
 #include <stdlib.h>
 #include <ctype.h>
 #include <string.h>
+#include <limits.h>
+#include <errno.h>
 
 static void tinymix_list_controls(struct mixer *mixer);
 static void tinymix_detail_control(struct mixer *mixer, const char *control,
@@ -175,6 +177,20 @@ static void tinymix_detail_control(struct mixer *mixer, const char *control,
     printf("\n");
 }
 
+static int is_int(char *value)
+{
+    char* end;
+    long int result;
+
+    errno = 0;
+    result = strtol(value, &end, 10);
+
+    if (result == LONG_MIN || result == LONG_MAX)
+        return 0;
+
+    return errno == 0 && *end == '\0';
+}
+
 static void tinymix_set_value(struct mixer *mixer, const char *control,
                               char **values, unsigned int num_values)
 {
@@ -196,7 +212,7 @@ static void tinymix_set_value(struct mixer *mixer, const char *control,
     type = mixer_ctl_get_type(ctl);
     num_ctl_values = mixer_ctl_get_num_values(ctl);
 
-    if (isdigit(values[0][0])) {
+    if (is_int(values[0])) {
         if (num_values == 1) {
             /* Set all values the same */
             int value = atoi(values[0]);