diff --git a/tests/tcp_cmd.cpp b/tests/tcp_cmd.cpp
index 5bc79d8..a6ce4f4 100644
--- a/tests/tcp_cmd.cpp
+++ b/tests/tcp_cmd.cpp
@@ -109,9 +109,9 @@ static void tcp_cmd_parser(struct tcp_pcb* pcb, int argc, char** argv) {
             return;
         } if (argc == 4) {
             color_bg = 0xff000000;
-            color_bg |= (uint32_t)(atoi(argv[1]) && 0xff) << 16;
-            color_bg |= (uint32_t)(atoi(argv[2]) && 0xff) << 8;
-            color_bg |= (uint32_t)(atoi(argv[3]) && 0xff);
+            color_bg |= (uint32_t)strtol(argv[1], NULL, 10) << 16;
+            color_bg |= (uint32_t)strtol(argv[2], NULL, 10) << 8;
+            color_bg |= (uint32_t)strtol(argv[3], NULL, 10);
             return;
         }
         tcp_cmd_write(pcb, "Usage: bgcolor <background color>\n");
@@ -125,9 +125,9 @@ static void tcp_cmd_parser(struct tcp_pcb* pcb, int argc, char** argv) {
             return;
         } if (argc == 4) {
             color_txt = 0xff000000;
-            color_txt |= (uint32_t)(atoi(argv[1]) && 0xff) << 16;
-            color_txt |= (uint32_t)(atoi(argv[2]) && 0xff) << 8;
-            color_txt |= (uint32_t)(atoi(argv[3]) && 0xff);
+            color_txt |= (uint32_t)strtol(argv[1], NULL, 10) << 16;
+            color_txt |= (uint32_t)strtol(argv[2], NULL, 10) << 8;
+            color_txt |= (uint32_t)strtol(argv[3], NULL, 10);
             return;
         }
         tcp_cmd_write(pcb, "Usage: color 0x<txt color>\n");