diff --git a/libavfilter/vf_boxblur.c b/libavfilter/vf_boxblur.c
index 398014a0b9..676d2057cb 100644
--- a/libavfilter/vf_boxblur.c
+++ b/libavfilter/vf_boxblur.c
@@ -144,8 +144,8 @@ static int config_input(AVFilterLink *inlink)
     char *expr;
     int ret;
 
-    if (!(boxblur->temp[0] = av_malloc(w)) ||
-        !(boxblur->temp[1] = av_malloc(w)))
+    if (!(boxblur->temp[0] = av_malloc(FFMAX(w, h))) ||
+        !(boxblur->temp[1] = av_malloc(FFMAX(w, h))))
         return AVERROR(ENOMEM);
 
     boxblur->hsub = desc->log2_chroma_w;