diff --git a/pages/UI.php b/pages/UI.php
index a6f76a329..7bf8491e8 100644
--- a/pages/UI.php
+++ b/pages/UI.php
@@ -564,7 +564,7 @@ try
 						$sFullText = trim($aMatches[2]);
 					}
 				}
-				
+				$sFullText = str_replace('_', '\_', $sFullText);
 				if (preg_match('/^"(.*)"$/', $sFullText, $aMatches))
 				{
 					// The text is surrounded by double-quotes, remove the quotes and treat it as one single expression
@@ -596,7 +596,7 @@ try
 					break;
 				}
 				$sFullText = implode(' ', $aFullTextNeedles);
-
+				$sFullText = str_replace('\_', '_', $sFullText);
 				// Sanity check of the accelerators
 				/** @var array $aAccelerators */
 				$aAccelerators = MetaModel::GetConfig()->Get('full_text_accelerators');
diff --git a/sources/application/search/criterionconversion/criteriontooql.class.inc.php b/sources/application/search/criterionconversion/criteriontooql.class.inc.php
index 0c70778d2..cc90ae6f8 100644
--- a/sources/application/search/criterionconversion/criteriontooql.class.inc.php
+++ b/sources/application/search/criterionconversion/criteriontooql.class.inc.php
@@ -123,6 +123,7 @@ class CriterionToOQL extends CriterionConversionAbstract
 		{
 			return "1";
 		}
+		$sValue = str_replace('_', '\_', $sValue);
 
 		return "({$sRef} LIKE '%{$sValue}%')";
 	}