diff --git a/src/V3Ast.cpp b/src/V3Ast.cpp
index 973814442..995fd1b5c 100644
--- a/src/V3Ast.cpp
+++ b/src/V3Ast.cpp
@@ -97,18 +97,17 @@ AstNode* AstNode::abovep() const {
 string AstNode::encodeName(const string& namein) {
     // Encode signal name raw from parser, then not called again on same signal
     string out;
-    for (string::const_iterator pos = namein.begin(); pos != namein.end(); ++pos) {
+    out.reserve(namein.size());
+    for (auto pos = namein.begin(); pos != namein.end(); ++pos) {
         if ((pos == namein.begin()) ? std::isalpha(pos[0])  // digits can't lead identifiers
                                     : std::isalnum(pos[0])) {
             out += pos[0];
         } else if (pos[0] == '_') {
+            out += pos[0];
+            if (pos + 1 == namein.end()) break;
             if (pos[1] == '_') {
-                out += "_";
-                out += "__05F";  // hex(_) = 0x5F
                 ++pos;
-                if (pos == namein.end()) break;
-            } else {
-                out += pos[0];
+                out += "__05F";  // hex(_) = 0x5F
             }
         } else {
             // Need the leading 0 so this will never collide with
diff --git a/test_regress/t/t_var_escape.out b/test_regress/t/t_var_escape.out
index 48b83ad17..7517b1831 100644
--- a/test_regress/t/t_var_escape.out
+++ b/test_regress/t/t_var_escape.out
@@ -11,9 +11,11 @@ $timescale 1ps $end
    $var wire 1 # clk $end
    $var wire 32 ( cyc [31:0] $end
    $var wire 1 $ escaped_normal $end
-   $var wire 1 $ double__underscore $end
-   $var wire 1 $ 9num $end
-   $var wire 1 $ bra[ket]slash/dash-colon:9backslash\done $end
+   $var wire 1 % double__underscore $end
+   $var wire 1 $ underscore_at_the_end_ $end
+   $var wire 1 $ double__underscore_at_the_end__ $end
+   $var wire 1 & 9num $end
+   $var wire 1 ' bra[ket]slash/dash-colon:9backslash\done $end
    $var wire 1 $ wire $end
    $var wire 1 $ check_alias $end
    $var wire 1 $ check:alias $end
diff --git a/test_regress/t/t_var_escape.v b/test_regress/t/t_var_escape.v
index bc2b38ea5..910c61332 100644
--- a/test_regress/t/t_var_escape.v
+++ b/test_regress/t/t_var_escape.v
@@ -21,6 +21,15 @@ module t (/*AUTOARG*/
    output  double__underscore ;
    wire  double__underscore = cyc[0];
 
+   wire  underscore_at_the_end_          = cyc[0];
+   wire  double__underscore_at_the_end__ = cyc[0];
+
+   // Only underscores, ignored in trace
+   wire  _    = cyc[0];
+   wire  __   = cyc[0];
+   wire  ___  = cyc[0];
+   wire  ____ = cyc[0];
+
    // C doesn't allow leading non-alpha, so must escape
    output \9num ;
    wire \9num = cyc[0];
@@ -45,7 +54,12 @@ module t (/*AUTOARG*/
       cyc <= cyc + 1;
       if (escaped_normal != cyc[0]) $stop;
       if (\escaped_normal != cyc[0]) $stop;
-      if (double__underscore != cyc[0]) $stop;
+      if (underscore_at_the_end_ != cyc[0]) $stop;
+      if (double__underscore_at_the_end__ != cyc[0]) $stop;
+      if (_ != cyc[0]) $stop;
+      if (__ != cyc[0]) $stop;
+      if (___ != cyc[0]) $stop;
+      if (____ != cyc[0]) $stop;
       if (\9num != cyc[0]) $stop;
       if (\bra[ket]slash/dash-colon:9backslash\done != cyc[0]) $stop;
       if (\wire != cyc[0]) $stop;