diff --git a/nodist/invoke_vcs b/nodist/invoke_vcs
index ec563103f..b3ee1d47c 100755
--- a/nodist/invoke_vcs
+++ b/nodist/invoke_vcs
@@ -8,7 +8,7 @@ use strict;
 #======================================================================
 # main
 
-eval `modulecmd perl add synopsys-vcs`;
+eval `modulecmd perl add synopsys-vcs_mx`;
 exec('vcs',@ARGV);
 
 #######################################################################
diff --git a/src/V3Width.cpp b/src/V3Width.cpp
index 4c10be815..9434c7486 100644
--- a/src/V3Width.cpp
+++ b/src/V3Width.cpp
@@ -2231,14 +2231,14 @@ private:
     }
     AstNodeBiop* iterate_shift_final(AstNodeBiop* nodep, AstNUser* vup)  {
 	// Nodep maybe edited
-	if (vup->c()->prelim()) {
+	if (vup->c()->final()) {
 	    // ShiftRS converts to ShiftR, but not vice-versa
 	    if (nodep->castShiftRS()) {
 		if (AstNodeBiop* newp=replaceWithUOrSVersion(nodep, nodep->isSigned())) { nodep=NULL;
 		    nodep = newp;  // Process new node instead
 		}
 	    }
-	    AstNodeDType* expDTypep = nodep->dtypep();
+	    AstNodeDType* expDTypep = vup->c()->dtypeOverridep(nodep->dtypep());
 	    AstNodeDType* subDTypep = expDTypep;
 	    nodep->dtypeFrom(expDTypep);
 	    iterateCheck(nodep,"LHS",nodep->lhsp(),CONTEXT,FINAL,subDTypep,EXTEND_EXP);
diff --git a/test_regress/t/t_math_signed4.v b/test_regress/t/t_math_signed4.v
index 9f9bb3fd7..fc70fc6c9 100644
--- a/test_regress/t/t_math_signed4.v
+++ b/test_regress/t/t_math_signed4.v
@@ -91,6 +91,12 @@ module t (/*AUTOARG*/);
       w4_u = 5'b10000 / 5'b00100;
       `checkh(w4_u, 4'b0100);
 
+      // bug754
+      w5_u = 4'sb0010 << -2'sd1;  // << 3
+      `checkh(w5_u, 5'b10000);  // VCS E-2014.03 bug
+      w5_u = 4'sb1000 << 0;   // Sign extends
+      `checkh(w5_u, 5'b11000);
+
       // Reals do not propagate to children
       r = 1.0 + ( 1 + (1 / 2));
       `checkf(r, 2.0);