diff --git a/inc/custom-comments.php b/inc/custom-comments.php
index 429b3f1..ea5d0cd 100644
--- a/inc/custom-comments.php
+++ b/inc/custom-comments.php
@@ -15,25 +15,29 @@ add_filter( 'comment_form_default_fields', 'understrap_bootstrap_comment_form_fi
  *
  * @return array
  */
-function understrap_bootstrap_comment_form_fields( $fields ) {
-	$commenter = wp_get_current_commenter();
-	$req       = get_option( 'require_name_email' );
-	$aria_req  = ( $req ? " aria-required='true'" : '' );
-	$html5     = current_theme_supports( 'html5', 'comment-form' ) ? 1 : 0;
-	$fields    = array(
-		'author' => '<div class="form-group comment-form-author"><label for="author">' . __( 'Name',
-				'understrap' ) . ( $req ? ' <span class="required">*</span>' : '' ) . '</label> ' .
-		            '<input class="form-control" id="author" name="author" type="text" value="' . esc_attr( $commenter['comment_author'] ) . '" size="30"' . $aria_req . '></div>',
-		'email'  => '<div class="form-group comment-form-email"><label for="email">' . __( 'Email',
-				'understrap' ) . ( $req ? ' <span class="required">*</span>' : '' ) . '</label> ' .
-		            '<input class="form-control" id="email" name="email" ' . ( $html5 ? 'type="email"' : 'type="text"' ) . ' value="' . esc_attr( $commenter['comment_author_email'] ) . '" size="30"' . $aria_req . '></div>',
-		'url'    => '<div class="form-group comment-form-url"><label for="url">' . __( 'Website',
-				'understrap' ) . '</label> ' .
-		            '<input class="form-control" id="url" name="url" ' . ( $html5 ? 'type="url"' : 'type="text"' ) . ' value="' . esc_attr( $commenter['comment_author_url'] ) . '" size="30"></div>',
-	);
 
-	return $fields;
-}
+if ( ! function_exists( 'understrap_bootstrap_comment_form_fields' ) ) {
+
+	function understrap_bootstrap_comment_form_fields( $fields ) {
+		$commenter = wp_get_current_commenter();
+		$req       = get_option( 'require_name_email' );
+		$aria_req  = ( $req ? " aria-required='true'" : '' );
+		$html5     = current_theme_supports( 'html5', 'comment-form' ) ? 1 : 0;
+		$fields    = array(
+			'author' => '<div class="form-group comment-form-author"><label for="author">' . __( 'Name',
+					'understrap' ) . ( $req ? ' <span class="required">*</span>' : '' ) . '</label> ' .
+			            '<input class="form-control" id="author" name="author" type="text" value="' . esc_attr( $commenter['comment_author'] ) . '" size="30"' . $aria_req . '></div>',
+			'email'  => '<div class="form-group comment-form-email"><label for="email">' . __( 'Email',
+					'understrap' ) . ( $req ? ' <span class="required">*</span>' : '' ) . '</label> ' .
+			            '<input class="form-control" id="email" name="email" ' . ( $html5 ? 'type="email"' : 'type="text"' ) . ' value="' . esc_attr( $commenter['comment_author_email'] ) . '" size="30"' . $aria_req . '></div>',
+			'url'    => '<div class="form-group comment-form-url"><label for="url">' . __( 'Website',
+					'understrap' ) . '</label> ' .
+			            '<input class="form-control" id="url" name="url" ' . ( $html5 ? 'type="url"' : 'type="text"' ) . ' value="' . esc_attr( $commenter['comment_author_url'] ) . '" size="30"></div>',
+		);
+
+		return $fields;
+	}
+} // endif function_exists( 'understrap_bootstrap_comment_form_fields' )
 
 add_filter( 'comment_form_defaults', 'understrap_bootstrap_comment_form' );
 
@@ -44,11 +48,15 @@ add_filter( 'comment_form_defaults', 'understrap_bootstrap_comment_form' );
  *
  * @return mixed
  */
-function understrap_bootstrap_comment_form( $args ) {
-	$args['comment_field'] = '<div class="form-group comment-form-comment">
-    <label for="comment">' . _x( 'Comment', 'noun', 'understrap' ) . ( ' <span class="required">*</span>' ) . '</label>
-    <textarea class="form-control" id="comment" name="comment" aria-required="true" cols="45" rows="8"></textarea>
-    </div>';
-	$args['class_submit']  = 'btn btn-secondary'; // since WP 4.1.
-	return $args;
-}
+
+if ( ! function_exists( 'understrap_bootstrap_comment_form' ) ) {
+
+	function understrap_bootstrap_comment_form( $args ) {
+		$args['comment_field'] = '<div class="form-group comment-form-comment">
+	    <label for="comment">' . _x( 'Comment', 'noun', 'understrap' ) . ( ' <span class="required">*</span>' ) . '</label>
+	    <textarea class="form-control" id="comment" name="comment" aria-required="true" cols="45" rows="8"></textarea>
+	    </div>';
+		$args['class_submit']  = 'btn btn-secondary'; // since WP 4.1.
+		return $args;
+	}
+} // endif function_exists( 'understrap_bootstrap_comment_form' )