diff --git a/HISTORY.TXT b/HISTORY.TXT
index ff08050728..ba0050b113 100644
--- a/HISTORY.TXT
+++ b/HISTORY.TXT
@@ -14,6 +14,8 @@ For a complete change history, please see the Git log comments.
 Current Version (future 6.2.0-beta2, GIT branch-6-2):
 -------------------------------------------------
 
+- Fix segfault in queryByFilter function in PHP/MapScript
+
 - Adjusted mediatype to multipart/related in WCS 2.0 (#4003)
 
 - Fix symbolObj.getImage seg fault in PHP/MapScript
diff --git a/mapscript/php/mapscript_i.c b/mapscript/php/mapscript_i.c
index 3fe1af8c1a..7fb400ca36 100644
--- a/mapscript/php/mapscript_i.c
+++ b/mapscript/php/mapscript_i.c
@@ -213,6 +213,9 @@ int mapObj_queryByFilter(mapObj* self, char *string)
   self->query.type = MS_QUERY_BY_FILTER;
 
   self->query.filter = (expressionObj *) malloc(sizeof(expressionObj));
+  self->query.filter->compiled = MS_FALSE;
+  self->query.filter->flags = 0;
+  self->query.filter->tokens = self->query.filter->curtoken = NULL;
   self->query.filter->string = strdup(string);
   self->query.filter->type = 2000; /* MS_EXPRESSION: lot's of conflicts in mapfile.h */
 
@@ -696,6 +699,9 @@ int layerObj_queryByFilter(layerObj *self, mapObj *map, char *string)
   map->query.filter = (expressionObj *) malloc(sizeof(expressionObj));
   map->query.filter->string = strdup(string);
   map->query.filter->type = 2000; /* MS_EXPRESSION: lot's of conflicts in mapfile.h */
+  map->query.filter->compiled = MS_FALSE;
+  map->query.filter->flags = 0;
+  map->query.filter->tokens = map->query.filter->curtoken = NULL;
 
   map->query.layer = self->index;
   map->query.rect = map->extent;