diff --git a/17-Test-Bias.Rmd b/17-Test-Bias.Rmd
index 592583f5..ae9aaa76 100644
--- a/17-Test-Bias.Rmd
+++ b/17-Test-Bias.Rmd
@@ -902,6 +902,7 @@ mydataBias <- cbind(
       ncol = dimensionsDf[2])))
 names(mydataBias) <- varNames
 
+data("HolzingerSwineford1939")
 varNames <- names(HolzingerSwineford1939)
 dimensionsDf <- dim(HolzingerSwineford1939[,paste("x", 1:9, sep = "")])
 unlistedDf <- unlist(HolzingerSwineford1939[,paste("x", 1:9, sep = "")])