diff --git a/prism/src/explicit/ConstructModel.java b/prism/src/explicit/ConstructModel.java
index 81fe13e3..7e2d62b5 100644
--- a/prism/src/explicit/ConstructModel.java
+++ b/prism/src/explicit/ConstructModel.java
@@ -144,7 +144,7 @@ public class ConstructModel extends PrismComponent
 		
 		// Display a warning if there are unbounded vars
 		VarList varList = modulesFile.createVarList();
-		if (varList.containsUnboundedVariables())
+		if (modulesFile.containsUnboundedVariables())
 			mainLog.printWarning("Model contains one or more unbounded variables: model construction may not terminate");
 
 		// Starting reachability...
diff --git a/prism/src/parser/VarList.java b/prism/src/parser/VarList.java
index 08d32e91..99675e06 100644
--- a/prism/src/parser/VarList.java
+++ b/prism/src/parser/VarList.java
@@ -487,21 +487,6 @@ public class VarList
 		return state;
 	}
 
-	/**
-	 * Does the variable list contain any variables with unbounded range (e.g. "clock: or "int")?
-	 */
-	public boolean containsUnboundedVariables()
-	{
-		int n = getNumVars();
-		for (int i = 0; i < n; i++) {
-			DeclarationType declType = getDeclaration(i).getDeclType();
-			if (declType instanceof DeclarationClock || declType instanceof DeclarationIntUnbounded) {
-				return true;
-			}
-		}
-		return false;
-	}
-	
 	/**
 	 * Clone this list.
 	 */
diff --git a/prism/src/parser/ast/ModulesFile.java b/prism/src/parser/ast/ModulesFile.java
index a0613efb..9836df7a 100644
--- a/prism/src/parser/ast/ModulesFile.java
+++ b/prism/src/parser/ast/ModulesFile.java
@@ -558,6 +558,18 @@ public class ModulesFile extends ASTElement
 		return false;
 	}
 
+	public boolean containsUnboundedVariables()
+	{
+		int n = getNumVars();
+		for (int i = 0; i < n; i++) {
+			DeclarationType declType = getVarDeclaration(i).getDeclType();
+			if (declType instanceof DeclarationClock || declType instanceof DeclarationIntUnbounded) {
+				return true;
+			}
+		}
+		return false;
+	}
+	
 	/**
 	 * Method to "tidy up" after parsing (must be called)
 	 * (do some checks and extract some information)
diff --git a/prism/src/prism/Modules2MTBDD.java b/prism/src/prism/Modules2MTBDD.java
index c10ec384..9207b312 100644
--- a/prism/src/prism/Modules2MTBDD.java
+++ b/prism/src/prism/Modules2MTBDD.java
@@ -180,7 +180,7 @@ public class Modules2MTBDD
 		
 		// get variable info from ModulesFile
 		varList = modulesFile.createVarList();
-		if (varList.containsUnboundedVariables())
+		if (modulesFile.containsUnboundedVariables())
 			throw new PrismNotSupportedException("Cannot build a model that contains a variable with unbounded range (try the explicit engine instead)");
 		numVars = varList.getNumVars();
 		constantValues = modulesFile.getConstantValues();