diff --git a/htdocs/core/lib/pdf.lib.php b/htdocs/core/lib/pdf.lib.php
index ce82c0a2817..1f9bcc20cd7 100644
--- a/htdocs/core/lib/pdf.lib.php
+++ b/htdocs/core/lib/pdf.lib.php
@@ -345,7 +345,7 @@ function pdf_build_address($outputlangs,$sourcecompany,$targetcompany='',$target
 				// Phone
 				if (! empty($targetcontact->phone_pro) || ! empty($targetcontact->phone_mobile)) $stringaddress .= ($stringaddress ? "\n" : '' ).$outputlangs->transnoentities("Phone").": ";
 				if (! empty($targetcontact->phone_pro)) $stringaddress .= $outputlangs->convToOutputCharset($targetcontact->phone_pro);
-				if (! empty($targetcontact->phone_pro) || ! empty($targetcontact->phone_mobile)) $stringaddress .= " / ";
+				if (! empty($targetcontact->phone_pro) && ! empty($targetcontact->phone_mobile)) $stringaddress .= " / ";
 				if (! empty($targetcontact->phone_mobile)) $stringaddress .= $outputlangs->convToOutputCharset($targetcontact->phone_mobile);
 				// Fax
 				if ($targetcontact->fax) $stringaddress .= ($stringaddress ? "\n" : '' ).$outputlangs->transnoentities("Fax").": ".$outputlangs->convToOutputCharset($targetcontact->fax);
@@ -366,7 +366,7 @@ function pdf_build_address($outputlangs,$sourcecompany,$targetcompany='',$target
 				// Phone
 				if (! empty($targetcompany->phone) || ! empty($targetcompany->phone_mobile)) $stringaddress .= ($stringaddress ? "\n" : '' ).$outputlangs->transnoentities("Phone").": ";
 				if (! empty($targetcompany->phone)) $stringaddress .= $outputlangs->convToOutputCharset($targetcompany->phone);
-				if (! empty($targetcompany->phone) || ! empty($targetcompany->phone_mobile)) $stringaddress .= " / ";
+				if (! empty($targetcompany->phone) && ! empty($targetcompany->phone_mobile)) $stringaddress .= " / ";
 				if (! empty($targetcompany->phone_mobile)) $stringaddress .= $outputlangs->convToOutputCharset($targetcompany->phone_mobile);
 				// Fax
 				if ($targetcompany->fax) $stringaddress .= ($stringaddress ? "\n" : '' ).$outputlangs->transnoentities("Fax").": ".$outputlangs->convToOutputCharset($targetcompany->fax);