diff --git a/main/src/com/google/refine/InterProjectModel.java b/main/src/com/google/refine/InterProjectModel.java
index 295042612..eb69aec47 100644
--- a/main/src/com/google/refine/InterProjectModel.java
+++ b/main/src/com/google/refine/InterProjectModel.java
@@ -97,13 +97,13 @@ public class InterProjectModel {
      * @param toColumn
      * @return
      */
-    public ProjectJoin getJoin(String fromProject, String fromColumn, String toProject, String toColumn) {
+    public ProjectJoin getJoin(Long fromProject, String fromColumn, Long toProject, String toColumn) {
         String key = fromProject + ";" + fromColumn + ";" + toProject + ";" + toColumn;
         if (!_joins.containsKey(key)) {
             ProjectJoin join = new ProjectJoin(
-                ProjectManager.singleton.getProjectID(fromProject), 
+                fromProject, 
                 fromColumn, 
-                ProjectManager.singleton.getProjectID(toProject), 
+                toProject, 
                 toColumn
             );
             
diff --git a/main/src/com/google/refine/ProjectManager.java b/main/src/com/google/refine/ProjectManager.java
index 66f2e6dcd..89070ac29 100644
--- a/main/src/com/google/refine/ProjectManager.java
+++ b/main/src/com/google/refine/ProjectManager.java
@@ -33,6 +33,7 @@ OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 
 package com.google.refine;
 
+import com.google.refine.util.GetProjectIDException;
 import java.io.IOException;
 import java.io.InputStream;
 import java.time.LocalDateTime;
@@ -383,15 +384,26 @@ public abstract class ProjectManager {
      * @param name
      *     The name of the project
      * @return
-     *     The id of the project, or -1 if it cannot be found
+     *     The id of the project
+     * @throws GetProjectIDException
+     *     If no unique project is found with the given name
      */
-    public long getProjectID(String name) {
+    public long getProjectID(String name) throws GetProjectIDException {
+        Integer c = 0;
+        Long id = 0L;
         for (Entry<Long, ProjectMetadata> entry : _projectsMetadata.entrySet()) {
             if (entry.getValue().getName().equals(name)) {
-                return entry.getKey();
+                id = entry.getKey();
+                c += 1;
             }
         }
-        return -1;
+        if (c == 1) {
+            return id;
+        } else if (c == 0) {
+            throw new GetProjectIDException("Unable to find project with name: " + name); 
+        } else {
+            throw new GetProjectIDException(c + " projects found with name: " + name); 
+        }
     }
     
     /**
diff --git a/main/src/com/google/refine/expr/functions/Cross.java b/main/src/com/google/refine/expr/functions/Cross.java
index b9ed764f2..07ecee5da 100644
--- a/main/src/com/google/refine/expr/functions/Cross.java
+++ b/main/src/com/google/refine/expr/functions/Cross.java
@@ -33,6 +33,7 @@ OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 
 package com.google.refine.expr.functions;
 
+import com.google.refine.util.GetProjectIDException;
 import java.util.Properties;
 
 import com.google.refine.InterProjectModel.ProjectJoin;
@@ -51,17 +52,27 @@ public class Cross implements Function {
             // 1st argument can take either value or cell(for backward compatibility)
             Object v = args[0];
             Object toProjectName = args[1];
-            Object toColumnName = args[2];
+            Object toColumnName = args[2]; 
+            Long toProjectID;           
             
             if (v != null && 
                 ( v instanceof String || v instanceof WrappedCell ) &&
                 toProjectName != null && toProjectName instanceof String &&
                 toColumnName != null && toColumnName instanceof String) {
-                
+                try {
+                    toProjectID = ProjectManager.singleton.getProjectID((String) toProjectName);
+                } catch (GetProjectIDException e){
+                    return new EvalError(e.getMessage());
+                }
                 ProjectJoin join = ProjectManager.singleton.getInterProjectModel().getJoin(
-                        ProjectManager.singleton.getProjectMetadata(((Project) bindings.get("project")).id).getName(),
+                        // getJoin(Long fromProject, String fromColumn, Long toProject, String toColumn) {
+                        // source project name 
+                        (Long) ((Project) bindings.get("project")).id,
+                        // source column name
                         (String) bindings.get("columnName"), 
-                        (String) toProjectName, 
+                        // target project name
+                        toProjectID,
+                        // target column name
                         (String) toColumnName
                         );
                 if(v instanceof String) {