diff --git a/Changes b/Changes
index 8a0ffe606..abf2b9543 100644
--- a/Changes
+++ b/Changes
@@ -22,7 +22,7 @@ The contributors that suggested a given feature are shown in []. Thanks!
 
 ****  Fix ugly error on interface misuse, bug1525. [Bogdan Vukobratovic]
 
-****  Fix misc bad-syntax crashes, bug1529-bug1530, bug1532. [Eric Rippey]
+****  Fix misc bad-syntax crashes, bug1529-bug1533. [Eric Rippey]
 
 
 * Verilator 4.018 2019-08-29
diff --git a/src/V3Ast.cpp b/src/V3Ast.cpp
index bf9fd40ac..40bcf9d7a 100644
--- a/src/V3Ast.cpp
+++ b/src/V3Ast.cpp
@@ -113,7 +113,8 @@ string AstNode::encodeName(const string& namein) {
             // a user identifier nor a temp we create in Verilator.
             // We also do *NOT* use __DOT__ etc, as we search for those
             // in some replacements, and don't want to mangle the user's names.
-            char hex[10]; sprintf(hex, "__0%02X", pos[0]);
+            unsigned val = pos[0] & 0xff;  // Mask to avoid sign extension
+            char hex[10]; sprintf(hex, "__0%02X", val);
             out += hex;
         }
     }