diff --git a/cxx/mcc_mount_astro_erfa.h b/cxx/mcc_mount_astro_erfa.h
index cda7082..be9a28f 100644
--- a/cxx/mcc_mount_astro_erfa.h
+++ b/cxx/mcc_mount_astro_erfa.h
@@ -158,7 +158,7 @@ public:
     }
 
 
-    engine_err_t terrestialTime(juldate_t juldate, juldate_t& tt)
+    engine_err_t terrestrialTime(juldate_t juldate, juldate_t& tt)
     {
         std::lock_guard lock{_stateMutex};
 
@@ -213,7 +213,7 @@ public:
         // gst = eraGst06a(juldate.MJD0, ut1, juldate.MJD0, tt);
 
         juldate_t tt;
-        auto err = terrestialTime(juldate, tt);
+        auto err = terrestrialTime(juldate, tt);
         if (err != ERROR_OK) {
             return err;
         }
@@ -231,7 +231,7 @@ public:
     {
         juldate_t tt;
 
-        auto err = terrestialTime(juldate, tt);
+        auto err = terrestrialTime(juldate, tt);
         if (err != ERROR_OK) {
             return err;
         }