diff --git a/libvips.supp b/libvips.supp
index aefca16d..42244c8b 100644
--- a/libvips.supp
+++ b/libvips.supp
@@ -153,6 +153,22 @@
    fun:FcPatternAddInteger
 }
 
+{
+   fontconfig5
+   Memcheck:Leak
+   fun:realloc
+   ...
+   fun:FcPatternDuplicate
+}
+
+{
+   fontconfig6
+   Memcheck:Leak
+   fun:realloc
+   ...
+   fun:FcDefaultSubstitute
+}
+
 {
    freetype_init
    Memcheck:Leak