diff --git a/monitoring/instrumented_mutex.h b/monitoring/instrumented_mutex.h
index e05c6addd..ea29bb452 100644
--- a/monitoring/instrumented_mutex.h
+++ b/monitoring/instrumented_mutex.h
@@ -54,10 +54,9 @@ class InstrumentedMutex {
 class ALIGN_AS(CACHE_LINE_SIZE) CacheAlignedInstrumentedMutex
     : public InstrumentedMutex {
   using InstrumentedMutex::InstrumentedMutex;
-  char padding[(CACHE_LINE_SIZE - sizeof(InstrumentedMutex) % CACHE_LINE_SIZE) %
-               CACHE_LINE_SIZE] ROCKSDB_FIELD_UNUSED;
 };
-static_assert(sizeof(CacheAlignedInstrumentedMutex) % CACHE_LINE_SIZE == 0);
+static_assert(alignof(CacheAlignedInstrumentedMutex) != CACHE_LINE_SIZE ||
+              sizeof(CacheAlignedInstrumentedMutex) % CACHE_LINE_SIZE == 0);
 
 // RAII wrapper for InstrumentedMutex
 class InstrumentedMutexLock {