diff --git a/lib/std/Progress.zig b/lib/std/Progress.zig
index 8b741187e7..58d409ac07 100644
--- a/lib/std/Progress.zig
+++ b/lib/std/Progress.zig
@@ -1006,7 +1006,7 @@ fn serializeIpc(start_serialized_len: usize, serialized_buffer: *Serialized.Buff
                         continue;
                     }
                     const src = pipe_buf[m.remaining_read_trash_bytes..n];
-                    std.mem.copyForwards(u8, &pipe_buf, src);
+                    @memmove(pipe_buf[0..src.len], src);
                     m.remaining_read_trash_bytes = 0;
                     bytes_read = src.len;
                     continue;
diff --git a/lib/std/array_list.zig b/lib/std/array_list.zig
index c3fade794f..02e4608399 100644
--- a/lib/std/array_list.zig
+++ b/lib/std/array_list.zig
@@ -158,7 +158,7 @@ pub fn ArrayListAligned(comptime T: type, comptime alignment: ?mem.Alignment) ty
             assert(self.items.len < self.capacity);
             self.items.len += 1;
 
-            mem.copyBackwards(T, self.items[i + 1 .. self.items.len], self.items[i .. self.items.len - 1]);
+            @memmove(self.items[i + 1 .. self.items.len], self.items[i .. self.items.len - 1]);
             self.items[i] = item;
         }
 
@@ -216,7 +216,7 @@ pub fn ArrayListAligned(comptime T: type, comptime alignment: ?mem.Alignment) ty
             assert(self.capacity >= new_len);
             const to_move = self.items[index..];
             self.items.len = new_len;
-            mem.copyBackwards(T, self.items[index + count ..], to_move);
+            @memmove(self.items[index + count ..][0..to_move.len], to_move);
             const result = self.items[index..][0..count];
             @memset(result, undefined);
             return result;
@@ -746,7 +746,7 @@ pub fn ArrayListAlignedUnmanaged(comptime T: type, comptime alignment: ?mem.Alig
             assert(self.items.len < self.capacity);
             self.items.len += 1;
 
-            mem.copyBackwards(T, self.items[i + 1 .. self.items.len], self.items[i .. self.items.len - 1]);
+            @memmove(self.items[i + 1 .. self.items.len], self.items[i .. self.items.len - 1]);
             self.items[i] = item;
         }
 
@@ -782,7 +782,7 @@ pub fn ArrayListAlignedUnmanaged(comptime T: type, comptime alignment: ?mem.Alig
             assert(self.capacity >= new_len);
             const to_move = self.items[index..];
             self.items.len = new_len;
-            mem.copyBackwards(T, self.items[index + count ..], to_move);
+            @memmove(self.items[index + count ..][0..to_move.len], to_move);
             const result = self.items[index..][0..count];
             @memset(result, undefined);
             return result;
@@ -848,11 +848,8 @@ pub fn ArrayListAlignedUnmanaged(comptime T: type, comptime alignment: ?mem.Alig
             } else {
                 const extra = range.len - new_items.len;
                 @memcpy(range[0..new_items.len], new_items);
-                std.mem.copyForwards(
-                    T,
-                    self.items[after_range - extra ..],
-                    self.items[after_range..],
-                );
+                const src = self.items[after_range..];
+                @memmove(self.items[after_range - extra ..][0..src.len], src);
                 @memset(self.items[self.items.len - extra ..], undefined);
                 self.items.len -= extra;
             }
diff --git a/lib/std/math/big/int.zig b/lib/std/math/big/int.zig
index f07f5e422d..685dbead52 100644
--- a/lib/std/math/big/int.zig
+++ b/lib/std/math/big/int.zig
@@ -1710,7 +1710,7 @@ pub const Mutable = struct {
 
         if (xy_trailing != 0 and r.limbs[r.len - 1] != 0) {
             // Manually shift here since we know its limb aligned.
-            mem.copyBackwards(Limb, r.limbs[xy_trailing..], r.limbs[0..r.len]);
+            @memmove(r.limbs[xy_trailing..][0..r.len], r.limbs[0..r.len]);
             @memset(r.limbs[0..xy_trailing], 0);
             r.len += xy_trailing;
         }
@@ -3836,8 +3836,7 @@ fn llshl(r: []Limb, a: []const Limb, shift: usize) usize {
         std.debug.assert(@intFromPtr(r.ptr) >= @intFromPtr(a.ptr));
 
     if (shift == 0) {
-        if (a.ptr != r.ptr)
-            std.mem.copyBackwards(Limb, r[0..a.len], a);
+        if (a.ptr != r.ptr) @memmove(r[0..a.len], a);
         return a.len;
     }
     if (shift >= limb_bits) {
@@ -3891,8 +3890,7 @@ fn llshr(r: []Limb, a: []const Limb, shift: usize) usize {
     if (shift == 0) {
         std.debug.assert(r.len >= a.len);
 
-        if (a.ptr != r.ptr)
-            std.mem.copyForwards(Limb, r[0..a.len], a);
+        if (a.ptr != r.ptr) @memmove(r[0..a.len], a);
         return a.len;
     }
     if (shift >= limb_bits) {
diff --git a/lib/std/os/windows.zig b/lib/std/os/windows.zig
index 829a8c37cc..df325e1785 100644
--- a/lib/std/os/windows.zig
+++ b/lib/std/os/windows.zig
@@ -1332,7 +1332,7 @@ pub fn GetFinalPathNameByHandle(
             // dropping the \Device\Mup\ and making sure the path begins with \\
             if (mem.eql(u16, device_name_u16, std.unicode.utf8ToUtf16LeStringLiteral("Mup"))) {
                 out_buffer[0] = '\\';
-                mem.copyForwards(u16, out_buffer[1..][0..file_name_u16.len], file_name_u16);
+                @memmove(out_buffer[1..][0..file_name_u16.len], file_name_u16);
                 return out_buffer[0 .. 1 + file_name_u16.len];
             }
 
@@ -1400,7 +1400,7 @@ pub fn GetFinalPathNameByHandle(
                     if (out_buffer.len < drive_letter.len + file_name_u16.len) return error.NameTooLong;
 
                     @memcpy(out_buffer[0..drive_letter.len], drive_letter);
-                    mem.copyForwards(u16, out_buffer[drive_letter.len..][0..file_name_u16.len], file_name_u16);
+                    @memmove(out_buffer[drive_letter.len..][0..file_name_u16.len], file_name_u16);
                     const total_len = drive_letter.len + file_name_u16.len;
 
                     // Validate that DOS does not contain any spurious nul bytes.
@@ -1449,12 +1449,7 @@ pub fn GetFinalPathNameByHandle(
                     // to copy backwards. We also need to do this before copying the volume path because
                     // it could overwrite the file_name_u16 memory.
                     const file_name_dest = out_buffer[volume_path.len..][0..file_name_u16.len];
-                    const file_name_byte_offset = @intFromPtr(file_name_u16.ptr) - @intFromPtr(out_buffer.ptr);
-                    const file_name_index = file_name_byte_offset / @sizeOf(u16);
-                    if (volume_path.len > file_name_index)
-                        mem.copyBackwards(u16, file_name_dest, file_name_u16)
-                    else
-                        mem.copyForwards(u16, file_name_dest, file_name_u16);
+                    @memmove(file_name_dest, file_name_u16);
                     @memcpy(out_buffer[0..volume_path.len], volume_path);
                     const total_len = volume_path.len + file_name_u16.len;
 
diff --git a/src/Sema.zig b/src/Sema.zig
index 29c8daa8b3..5816990eb2 100644
--- a/src/Sema.zig
+++ b/src/Sema.zig
@@ -2631,7 +2631,7 @@ fn reparentOwnedErrorMsg(
 
     const orig_notes = msg.notes.len;
     msg.notes = try sema.gpa.realloc(msg.notes, orig_notes + 1);
-    std.mem.copyBackwards(Zcu.ErrorMsg, msg.notes[1..], msg.notes[0..orig_notes]);
+    @memmove(msg.notes[1..][0..orig_notes], msg.notes[0..orig_notes]);
     msg.notes[0] = .{
         .src_loc = msg.src_loc,
         .msg = msg.msg,
@@ -14464,8 +14464,8 @@ fn analyzeTupleMul(
             }
         }
         for (0..factor) |i| {
-            mem.copyForwards(InternPool.Index, types[tuple_len * i ..], types[0..tuple_len]);
-            mem.copyForwards(InternPool.Index, values[tuple_len * i ..], values[0..tuple_len]);
+            @memmove(types[tuple_len * i ..][0..tuple_len], types[0..tuple_len]);
+            @memmove(values[tuple_len * i ..][0..tuple_len], values[0..tuple_len]);
         }
         break :rs runtime_src;
     };