diff --git a/src/ripple/basics/SlabAllocator.h b/src/ripple/basics/SlabAllocator.h
index bd950123c6d..ece96d0b873 100644
--- a/src/ripple/basics/SlabAllocator.h
+++ b/src/ripple/basics/SlabAllocator.h
@@ -80,7 +80,7 @@ class SlabAllocator
             {
                 // Use memcpy to avoid unaligned UB
                 // (will optimize to equivalent code)
-                memcpy(data, &l_, sizeof(std::uint8_t*));
+                std::memcpy(data, &l_, sizeof(std::uint8_t*));
                 l_ = data;
                 data += item;
             }
@@ -122,7 +122,7 @@ class SlabAllocator
                 {
                     // Use memcpy to avoid unaligned UB
                     // (will optimize to equivalent code)
-                    memcpy(&l_, ret, sizeof(std::uint8_t*));
+                    std::memcpy(&l_, ret, sizeof(std::uint8_t*));
                 }
             }
 
@@ -147,7 +147,7 @@ class SlabAllocator
 
             // Use memcpy to avoid unaligned UB
             // (will optimize to equivalent code)
-            memcpy(ptr, &l_, sizeof(std::uint8_t*));
+            std::memcpy(ptr, &l_, sizeof(std::uint8_t*));
             l_ = ptr;
         }
     };
diff --git a/src/ripple/basics/impl/partitioned_unordered_map.cpp b/src/ripple/basics/impl/partitioned_unordered_map.cpp
index d7d2488f300..3ced32eddff 100644
--- a/src/ripple/basics/impl/partitioned_unordered_map.cpp
+++ b/src/ripple/basics/impl/partitioned_unordered_map.cpp
@@ -34,7 +34,7 @@ extract(uint256 const& key)
     std::size_t result;
     // Use memcpy to avoid unaligned UB
     // (will optimize to equivalent code)
-    memcpy(&result, key.data(), sizeof(std::size_t));
+    std::memcpy(&result, key.data(), sizeof(std::size_t));
     return result;
 }
 
diff --git a/src/ripple/beast/hash/impl/xxhash.cpp b/src/ripple/beast/hash/impl/xxhash.cpp
index 232c5a929da..4a6c85db815 100644
--- a/src/ripple/beast/hash/impl/xxhash.cpp
+++ b/src/ripple/beast/hash/impl/xxhash.cpp
@@ -33,6 +33,8 @@ You can contact the author at :
 
 #include <ripple/beast/hash/impl/xxhash.h>
 
+#include <cstring>
+
 //**************************************
 // Tuning parameters
 //**************************************
@@ -87,7 +89,7 @@ You can contact the author at :
 //**************************************
 // Includes & Memory related functions
 //**************************************
-//#include "xxhash.h"
+// #include "xxhash.h"
 // Modify the local functions below should you wish to use some other memory
 // routines for malloc(), free()
 #include <stdlib.h>
@@ -263,7 +265,7 @@ XXH_readLE64_align(const void* ptr, XXH_endianess endian, XXH_alignment align)
     {
         // Use memcpy to avoid unaligned UB
         U64 tmp_aligned;
-        memcpy(&tmp_aligned, ptr, sizeof(U64));
+        std::memcpy(&tmp_aligned, ptr, sizeof(U64));
         return endian == XXH_littleEndian ? tmp_aligned
                                           : XXH_swap64(tmp_aligned);
     }