diff --git a/libraries/AP_ESC_Telem/AP_ESC_Telem.cpp b/libraries/AP_ESC_Telem/AP_ESC_Telem.cpp
index de5e4d3d72..a1fdd777fd 100644
--- a/libraries/AP_ESC_Telem/AP_ESC_Telem.cpp
+++ b/libraries/AP_ESC_Telem/AP_ESC_Telem.cpp
@@ -89,9 +89,13 @@ uint8_t AP_ESC_Telem::get_num_active_escs() const {
 // get an individual ESC's slewed rpm if available, returns true on success
 bool AP_ESC_Telem::get_rpm(uint8_t esc_index, float& rpm) const
 {
+    if (esc_index >= ESC_TELEM_MAX_ESCS) {
+        return false;
+    }
+
     const volatile AP_ESC_Telem_Backend::RpmData& rpmdata = _rpm_data[esc_index];
 
-    if (esc_index >= ESC_TELEM_MAX_ESCS || is_zero(rpmdata.update_rate_hz)) {
+    if (is_zero(rpmdata.update_rate_hz)) {
         return false;
     }
 
@@ -108,12 +112,15 @@ bool AP_ESC_Telem::get_rpm(uint8_t esc_index, float& rpm) const
 // get an individual ESC's raw rpm if available, returns true on success
 bool AP_ESC_Telem::get_raw_rpm(uint8_t esc_index, float& rpm) const
 {
+    if (esc_index >= ESC_TELEM_MAX_ESCS) {
+        return false;
+    }
+
     const volatile AP_ESC_Telem_Backend::RpmData& rpmdata = _rpm_data[esc_index];
 
     const uint32_t now = AP_HAL::micros();
 
-    if (esc_index >= ESC_TELEM_MAX_ESCS || now < rpmdata.last_update_us
-        || now - rpmdata.last_update_us > ESC_RPM_DATA_TIMEOUT_US) {
+    if (now < rpmdata.last_update_us || now - rpmdata.last_update_us > ESC_RPM_DATA_TIMEOUT_US) {
         return false;
     }