diff --git a/src/detect-http-header.c b/src/detect-http-header.c
index e32220576b..f433d9fc9f 100644
--- a/src/detect-http-header.c
+++ b/src/detect-http-header.c
@@ -593,6 +593,8 @@ static void *HttpMultiBufHeaderThreadDataInit(void *data)
 
     /* This return value check to satisfy our Cocci malloc checks. */
     if (td == NULL) {
+        SCLogError("failed to allocate %" PRIuMAX " bytes: %s", (uintmax_t)sizeof(*td),
+                strerror(errno));
         return NULL;
     }
     return td;