diff --git a/src/terminal_api_driver.cpp b/src/terminal_api_driver.cpp
index 791f5fc..c7480ab 100644
--- a/src/terminal_api_driver.cpp
+++ b/src/terminal_api_driver.cpp
@@ -847,7 +847,7 @@ const static ModcodDef_t ModcodDefs[] = {
 static const char* extractModcodModulation(uint32_t modcod, bool defaultQpsk1_4 = true) {
     modcod >>= 2;
     const auto* d = defaultQpsk1_4 ? ModcodDefs : ModcodDefs + 1;
-    if (modcod < 28) {
+    if (modcod < (sizeof(ModcodDefs) / sizeof(ModcodDef_t))) {
         d = ModcodDefs + modcod;
     }
     return d->modulation;
@@ -856,7 +856,7 @@ static const char* extractModcodModulation(uint32_t modcod, bool defaultQpsk1_4
 static const char* extractModcodSpeed(uint32_t modcod, bool defaultQpsk1_4 = true) {
     modcod >>= 2;
     const auto* d = defaultQpsk1_4 ? ModcodDefs : ModcodDefs + 1;
-    if (modcod < 28) {
+    if (modcod < (sizeof(ModcodDefs) / sizeof(ModcodDef_t))) {
         d = ModcodDefs + modcod;
     }
     return d->speed;