diff --git a/render/glyph.c b/render/glyph.c
index cc982a038..19ad9cf0b 100644
--- a/render/glyph.c
+++ b/render/glyph.c
@@ -123,6 +123,10 @@ FindGlyphRef(GlyphHashPtr hash,
     CARD32 elt, step, s;
     GlyphPtr glyph;
     GlyphRefPtr table, gr, del;
+
+    if ((hash == NULL) || (hash->hashSet == NULL))
+        return NULL;
+
     CARD32 tableSize = hash->hashSet->size;
 
     table = hash->table;
@@ -267,7 +271,7 @@ FreeGlyph(GlyphPtr glyph, int format)
         gr = FindGlyphRef(&globalGlyphs[format], signature, TRUE, glyph->sha1);
         if (gr - globalGlyphs[format].table != first)
             DuplicateRef(glyph, "Found wrong one");
-        if (gr->glyph && gr->glyph != DeletedGlyph) {
+        if (gr && gr->glyph && gr->glyph != DeletedGlyph) {
             gr->glyph = DeletedGlyph;
             gr->signature = 0;
             globalGlyphs[format].tableEntries--;
@@ -384,6 +388,7 @@ AllocateGlyph(xGlyphInfo * gi, int fdepth)
 static Bool
 AllocateGlyphHash(GlyphHashPtr hash, GlyphHashSetPtr hashSet)
 {
+    assert(hashSet);
     hash->table = calloc(hashSet->size, sizeof(GlyphRefRec));
     if (!hash->table)
         return FALSE;
@@ -418,10 +423,10 @@ ResizeGlyphHash(GlyphHashPtr hash, CARD32 change, Bool global)
             glyph = hash->table[i].glyph;
             if (glyph && glyph != DeletedGlyph) {
                 s = hash->table[i].signature;
-                gr = FindGlyphRef(&newHash, s, global, glyph->sha1);
-
-                gr->signature = s;
-                gr->glyph = glyph;
+                if ((gr = FindGlyphRef(&newHash, s, global, glyph->sha1))) {
+                    gr->signature = s;
+                    gr->glyph = glyph;
+                }
                 ++newHash.tableEntries;
             }
         }