diff --git a/org.lamport.tla.toolbox.tool.tlc/src/org/lamport/tla/toolbox/tool/tlc/model/ModelWriter.java b/org.lamport.tla.toolbox.tool.tlc/src/org/lamport/tla/toolbox/tool/tlc/model/ModelWriter.java
index 4713750461e97b23cef648775a790d889c459622..07a6b3db685524e32e41bbbb04da46ea15aaceb5 100644
--- a/org.lamport.tla.toolbox.tool.tlc/src/org/lamport/tla/toolbox/tool/tlc/model/ModelWriter.java
+++ b/org.lamport.tla.toolbox.tool.tlc/src/org/lamport/tla/toolbox/tool/tlc/model/ModelWriter.java
@@ -1115,6 +1115,8 @@ public class ModelWriter
             // value of the constant expression in the TLC output
             tlaBuffer.append(COMMENT).append("Constant expression ASSUME statement ").append(ATTRIBUTE).append(
                     attributeName).append(CR);
+            // @see tlc2.module.MC
+            tlaBuffer.append("LOCAL PrintT(out) == TRUE").append(CR);
             tlaBuffer.append("ASSUME PrintT(").append(BEGIN_TUPLE).append(CONSTANT_EXPRESSION_EVAL_IDENTIFIER).append(
                     COMMA).append(id).append(END_TUPLE).append(")").append(CR);
             tlaBuffer.append(SEP).append(CR).append(CR);
diff --git a/org.lamport.tla.toolbox/src/org/lamport/tla/toolbox/util/ResourceHelper.java b/org.lamport.tla.toolbox/src/org/lamport/tla/toolbox/util/ResourceHelper.java
index 466f6b4692f962816d89e189976b12ccb4b26f2b..63ea70f5021b7352317af591ff45c2bb745d8256 100644
--- a/org.lamport.tla.toolbox/src/org/lamport/tla/toolbox/util/ResourceHelper.java
+++ b/org.lamport.tla.toolbox/src/org/lamport/tla/toolbox/util/ResourceHelper.java
@@ -776,7 +776,7 @@ public class ResourceHelper
     {
         StringBuffer buffer = new StringBuffer();
         buffer.append("---- MODULE ").append(ResourceHelper.getModuleNameChecked(moduleFilename, false)).append(
-                " ----\n").append("EXTENDS ").append(extendedModuleName).append(", TLC").append("\n\n");
+                " ----\n").append("EXTENDS ").append(extendedModuleName).append("\n\n");
         return buffer;
     }
 
diff --git a/tlatools/src/tlc2/module/BuiltInModuleHelper.java b/tlatools/src/tlc2/module/BuiltInModuleHelper.java
index ac0d789c7762064354e84942af9ceb9266312806..14f831f7cbde1436d5f74f211a0871c55665c96a 100644
--- a/tlatools/src/tlc2/module/BuiltInModuleHelper.java
+++ b/tlatools/src/tlc2/module/BuiltInModuleHelper.java
@@ -58,6 +58,8 @@ public class BuiltInModuleHelper {
 					return true;
 				} else if (clazz == TLC.class && value == TLC.serialVersionUID) {
 					return true;
+				} else if (clazz == MC.class && value == MC.serialVersionUID) {
+					return true;
 				} else if (clazz == TransitiveClosure.class && value == TransitiveClosure.serialVersionUID) {
 					return true;
 				}
diff --git a/tlatools/src/tlc2/module/MC.java b/tlatools/src/tlc2/module/MC.java
new file mode 100644
index 0000000000000000000000000000000000000000..9ffdb5d07ed6c3981ea8524e9ba90c694fa56745
--- /dev/null
+++ b/tlatools/src/tlc2/module/MC.java
@@ -0,0 +1,65 @@
+/*******************************************************************************
+ * Copyright (c) 2017 Microsoft Research. All rights reserved. 
+ *
+ * The MIT License (MIT)
+ * 
+ * Permission is hereby granted, free of charge, to any person obtaining a copy 
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies
+ * of the Software, and to permit persons to whom the Software is furnished to do
+ * so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in all
+ * copies or substantial portions of the Software. 
+ * 
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS
+ * FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR
+ * COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN
+ * AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
+ * WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+ *
+ * Contributors:
+ *   Markus Alexander Kuppe - initial API and implementation
+ ******************************************************************************/
+package tlc2.module;
+
+import tlc2.value.Value;
+
+/*
+ * The Toolbox generates an MC.tla file upon TLC startup which extends the actual
+ * specification being verified. Additionally, to evaluate any constant expression,
+ * MC.tla also extends TLC.tla to use the PrintT operator defined in TLC.tla 
+ * (and its module override tlc2.module.TLC):
+ * "ASSUME PrintT(...)"
+ * 
+ * Extending TLC.tla in MC.tla can cause a name clash if the actual specification
+ * does *not* extend TLC and happens to declare an operator colliding with one 
+ * in TLC.tla (e.g. "Permutations", "SortSeq", ...).
+ * 
+ * To resolve this name clash, the Toolbox no longer extends TLC.tla in MC.tla but
+ * instead generates a LOCAL declaration of PrintT:
+ * "LOCAL PrintT(out) == TRUE
+ *  ASSUME PrintT(...)"
+ * 
+ * TLC.tla's PrintT is override by the tlc2.module.TLC#PrintT module override.
+ * Thus, the LOCAL construct above only resolves the name clash at the SANY level,
+ * but produces no output. This class effectively associates MC.tla's PrintT with
+ * tlc2.module.TLC#PrintT.
+ * 
+ * The only operator for which this approach obviously does not work is PrintT itself.
+ * If the actual specification declares PrintT, evaluating a constant expression will
+ * fail. However - contrary to Permutations/SortSeq/... - this is handled gracefully
+ * with a proper error message.
+ * 
+ * @see org.lamport.tla.toolbox.tool.tlc.model.ModelWriter.addConstantExpressionEvaluation(String, String)
+ */
+public class MC {
+
+	public static final long serialVersionUID = 20171027L;
+
+	public static Value PrintT(Value v1) {
+		return TLC.PrintT(v1);
+	}
+}