diff --git a/R/onLoad.R b/R/onLoad.R
index d918db152..026327cd9 100644
--- a/R/onLoad.R
+++ b/R/onLoad.R
@@ -70,10 +70,11 @@
     # no delayed registration support for NAMESPACE; perform it manually
     if (isNamespaceLoaded("knitr")) {
       registerS3method("knit_print", "data.table", knit_print.data.table, envir = asNamespace("knitr"))
+    } else {
+      setHook(packageEvent("knitr", "onLoad"), function(...) {
+        registerS3method("knit_print", "data.table", knit_print.data.table, envir = asNamespace("knitr"))
+      })
     }
-    setHook(packageEvent("knitr", "onLoad"), function(...) {
-      registerS3method("knit_print", "data.table", knit_print.data.table, envir = asNamespace("knitr"))
-    })
   }
 
   # Set options for the speed boost in v1.8.0 by avoiding 'default' arg of getOption(,default=)