diff --git a/R/checkControl.R b/R/checkControl.R
index 4bcd8f1..09e5c21 100644
--- a/R/checkControl.R
+++ b/R/checkControl.R
@@ -11,6 +11,12 @@ checkControl <- function(control, fail = TRUE) {
 check.semtree.control <- function(control, fail = TRUE) {
   attr <- attributes(control)$names
   def.attr <- attributes(semtree.control())$names
+  
+  # add NULL-defaults
+  null_def <- c("min.N","min.bucket")
+  attr <- unique(c(attr, null_def))
+  def.attr <- unique(c(def.attr, null_def))
+  
   if ((length(intersect(attr, def.attr)) != length(attr))) {
     unknown <- setdiff(attr, def.attr)
     msg <-
diff --git a/R/checkModel.R b/R/checkModel.R
index bd2ded8..2c11479 100644
--- a/R/checkModel.R
+++ b/R/checkModel.R
@@ -24,6 +24,3 @@ checkModel <- function(model, control)
   
   return(TRUE);
 }
-
-#inherits(model1,"lavaan")
-#model1@Fit@converged
diff --git a/R/growTree.R b/R/growTree.R
index e47c4a3..630426b 100644
--- a/R/growTree.R
+++ b/R/growTree.R
@@ -64,7 +64,40 @@ growTree <- function(model = NULL, mydata = NULL,
       ui_message("Subsampled predictors: ", paste(node$colnames[meta$covariate.ids]))
     }
   }
+  
+  #   override forced split?
+  arguments <- list(...)
+  if ("forced_splits" %in% names(arguments) && !is.null(arguments$forced_splits)) {
+    forced_splits <- arguments$forced_splits
+    
+    # get names of model variables before forcing
+    model.names <- names(mydata)[meta$model.ids]
+    covariate.names <- names(mydata)[meta$covariate.ids]
+    
+    # select subset with model variables and single, forced predictor
+    forcedsplit.name <- forced_splits[1]
+    
+    if (control$verbose) {
+      cat("FORCED split: ",forcedsplit.name,"\n")
+    }
+    
 
+    mydata <- fulldata[, c(model.names, forcedsplit.name) ]
+    node$colnames <- colnames(mydata)
+    
+    # get new model ids after sampling by name
+    meta$model.ids <- sapply(model.names, function(x) {
+      which(x == names(mydata))
+    })
+    names(meta$model.ids) <- NULL
+    meta$covariate.ids <- unlist(lapply(covariate.names, function(x) {
+      which(x == names(mydata))
+    }))
+    
+  } else {
+    forced_splits <- NULL
+  }
+  
   # determine whether split evaluation can be done on p values
   node$p.values.valid <- control$method != "cv"
 
@@ -432,6 +465,31 @@ growTree <- function(model = NULL, mydata = NULL,
     mydata <- fulldata
     meta <- fullmeta
   }
+  
+  # restore mydata if forced split was true
+  # and (potentially) force continuation of splitting 
+  if (!is.null(forced_splits)) {
+    
+
+    # also need to remap col.max to original data!
+    if (!is.null(result$col.max) && !is.na(result$col.max)) {
+      col.max.name <- names(mydata)[result$col.max]
+      result$col.max <- which(names(fulldata) == col.max.name)
+    } else {
+      col.max.name <- NULL
+    }
+    
+    mydata <- fulldata
+    meta <- fullmeta
+    
+    # pop first element
+    forced_splits <- forced_splits[-1]
+    # set to NULL if no splits left
+    if (length(forced_splits)==0) forced_splits <- NULL
+    
+    # force continuation of splitting ?
+    cont.split <- TRUE
+  }
 
   if ((!is.null(cont.split)) && (!is.na(cont.split)) && (cont.split)) {
     if (control$report.level > 10) {
@@ -563,8 +621,8 @@ growTree <- function(model = NULL, mydata = NULL,
 
     # recursively continue splitting
     # result1 - RHS; result2 - LHS
-    result2 <- growTree(node$model, sub2, control, invariance, meta, edgelabel = 0, depth = depth + 1, constraints)
-    result1 <- growTree(node$model, sub1, control, invariance, meta, edgelabel = 1, depth = depth + 1, constraints)
+    result2 <- growTree(node$model, sub2, control, invariance, meta, edgelabel = 0, depth = depth + 1, constraints, forced_splits = forced_splits)
+    result1 <- growTree(node$model, sub1, control, invariance, meta, edgelabel = 1, depth = depth + 1, constraints, forced_splits = forced_splits)
 
     # store results in recursive list structure
     node$left_child <- result2
diff --git a/tests/control.R b/tests/control.R
index a247aa7..d7b4465 100644
--- a/tests/control.R
+++ b/tests/control.R
@@ -80,4 +80,15 @@ controlOptions <- semtree.control(method = "naive",max.depth = 0,min.N=NULL,
 tree <- semtree(model=lgcModel, data=lgcm, control = controlOptions)
 
 stopifnot(tree$control$min.N==50)
-stopifnot(tree$control$min.bucket==25)
\ No newline at end of file
+stopifnot(tree$control$min.bucket==25)
+
+
+
+x<-semtree_control()
+semtree:::check.semtree.control(x)
+
+x<-semtree_control(min.N=100)
+semtree:::check.semtree.control(x)
+
+x<-semtree_control(min.N=100, min.bucket=10)
+semtree:::check.semtree.control(x)
diff --git a/tests/testthat/forced_splitl.R b/tests/testthat/forced_splitl.R
new file mode 100644
index 0000000..b8cbdf7
--- /dev/null
+++ b/tests/testthat/forced_splitl.R
@@ -0,0 +1,28 @@
+library(lavaan)
+library(semtree)
+set.seed(1238)
+
+N <- 500
+
+# simulate data
+da <- data.frame(y = c(rnorm(N/2, mean = -1), rnorm(N/2, mean = 1)),
+                 z = factor(rep(c(0,1),each=N/2)),k=rnorm(N),m=rnorm(N) )
+
+m_lav <- '
+y ~~ y
+y ~ 1
+'
+
+fit_lav <- lavaan(model = m_lav, data = da)
+
+
+tree = semtree(model=fit_lav, data=da, 
+               control = semtree_control(method="score"),
+               forced_splits=NULL)
+
+
+
+tree_forced_m = semtree(model=fit_lav, data=da, 
+               control = semtree_control(method="score"),
+               forced_splits=c("m"))
+