diff --git a/esphome/core/time_64.cpp b/esphome/core/time_64.cpp
index cf651c3e91..25076228d5 100644
--- a/esphome/core/time_64.cpp
+++ b/esphome/core/time_64.cpp
@@ -22,8 +22,8 @@ static const char *const TAG = "time_64";
 
 #ifdef ESPHOME_THREAD_SINGLE
 // Storage for Millis64Impl inline compute() — defined here so all TUs share one copy.
-uint32_t Millis64Impl::last_millis_{0};
-uint16_t Millis64Impl::millis_major_{0};
+uint32_t Millis64Impl::last_millis{0};
+uint16_t Millis64Impl::millis_major{0};
 #else
 
 uint64_t Millis64Impl::compute(uint32_t now) {
diff --git a/esphome/core/time_64.h b/esphome/core/time_64.h
index 592e645d41..d82373dbfe 100644
--- a/esphome/core/time_64.h
+++ b/esphome/core/time_64.h
@@ -21,8 +21,8 @@ class Millis64Impl {
 
 #ifdef ESPHOME_THREAD_SINGLE
   // Storage defined in time_64.cpp — declared here so the inline body can access them.
-  static uint32_t last_millis_;
-  static uint16_t millis_major_;
+  static uint32_t last_millis;
+  static uint16_t millis_major;
 
   static inline uint64_t ESPHOME_ALWAYS_INLINE compute(uint32_t now) {
     // Half the 32-bit range - used to detect rollovers vs normal time progression
@@ -30,17 +30,17 @@ class Millis64Impl {
 
     // Single-core platforms have no concurrency, so this is a simple implementation
     // that just tracks 32-bit rollover (every 49.7 days) without any locking or atomics.
-    uint16_t major = millis_major_;
-    uint32_t last = last_millis_;
+    uint16_t major = millis_major;
+    uint32_t last = last_millis;
 
     // Check for rollover
     if (now < last && (last - now) > HALF_MAX_UINT32) {
-      millis_major_++;
+      millis_major++;
       major++;
-      last_millis_ = now;
+      last_millis = now;
     } else if (now > last) {
       // Only update if time moved forward
-      last_millis_ = now;
+      last_millis = now;
     }
 
     // Combine major (high 32 bits) and now (low 32 bits) into 64-bit time