diff --git a/R/output.R b/R/output.R
index 1b77c2ceae..6fead69da4 100644
--- a/R/output.R
+++ b/R/output.R
@@ -355,6 +355,12 @@ auto_format = function(ext) {
 #'
 #' # comment out the child doc by \Sexpr{knit_child('child-doc.Rnw', eval = FALSE)}
 knit_child = function(..., options = NULL, envir = knit_global()) {
+  old <- remove_all_hooks()
+  on.exit(restore_hooks(old), add = TRUE)
+  knit_child_unwrapped(..., options= options, envir = envir)
+}
+
+knit_child_unwrapped = function(..., options = NULL, envir = knit_global()) {
   child = child_mode()
   opts_knit$set(child = TRUE) # yes, in child mode now
   on.exit(opts_knit$set(child = child)) # restore child status
@@ -374,6 +380,26 @@ knit_child = function(..., options = NULL, envir = knit_global()) {
   paste(c('', res), collapse = '\n')
 }
 
+get_hook_names <- function() {
+  ls(.userHooksEnv, all.names = TRUE)
+}
+
+remove_all_hooks <- function() {
+  hook_names <-  get_hook_names()
+  old <- list()
+  for (hook_name in hook_names) {
+    old[[hook_name]] <- getHook(hook_name)
+    setHook(hook_name, NULL, action = "replace")
+  }
+  old
+}
+
+restore_hooks <- function(hooks) {
+  for (hook_name in names(hooks)) {
+    setHook(hook_name, hooks[[hook_name]], action = "replace")
+  }
+}
+
 #' Exit knitting early
 #'
 #' Sometimes we may want to exit the knitting process early, and completely