Index: src/wp-admin/includes/class-wp-plugins-list-table.php
===================================================================
--- src/wp-admin/includes/class-wp-plugins-list-table.php	(revision 39665)
+++ src/wp-admin/includes/class-wp-plugins-list-table.php	(working copy)
@@ -367,7 +367,7 @@
 		?>
 		<p class="search-box">
 			<label class="screen-reader-text" for="<?php echo esc_attr( $input_id ); ?>"><?php echo $text; ?>:</label>
-			<input type="search" id="<?php echo esc_attr( $input_id ); ?>" class="wp-filter-search" name="s" value="<?php _admin_search_query(); ?>" placeholder="<?php esc_attr_e( 'Search installed plugins...' ); ?>"/>
+			<input type="search" id="<?php echo esc_attr( $input_id ); ?>" class="wp-filter-search" name="s" value="<?php _admin_search_query(); ?>" placeholder="<?php esc_attr_e( 'Search installed plugins...' ); ?>" autocomplete="off"/>
 			<?php submit_button( $text, 'hide-if-js', '', false, array( 'id' => 'search-submit' ) ); ?>
 		</p>
 		<?php
Index: src/wp-admin/includes/plugin-install.php
===================================================================
--- src/wp-admin/includes/plugin-install.php	(revision 39665)
+++ src/wp-admin/includes/plugin-install.php	(working copy)
@@ -285,7 +285,7 @@
 			<option value="tag"<?php selected( 'tag', $type ); ?>><?php _ex( 'Tag', 'Plugin Installer' ); ?></option>
 		</select>
 		<label><span class="screen-reader-text"><?php _e( 'Search Plugins' ); ?></span>
-			<input type="search" name="s" value="<?php echo esc_attr( $term ) ?>" class="wp-filter-search" placeholder="<?php esc_attr_e( 'Search plugins...' ); ?>" />
+			<input type="search" name="s" value="<?php echo esc_attr( $term ) ?>" class="wp-filter-search" placeholder="<?php esc_attr_e( 'Search plugins...' ); ?>" autocomplete="off"/>
 		</label>
 		<?php submit_button( __( 'Search Plugins' ), 'hide-if-js', false, false, array( 'id' => 'search-submit' ) ); ?>
 	</form><?php