diff --git a/include/sta/ParseBus.hh b/include/sta/ParseBus.hh
index 45ee2691..df3ebec2 100644
--- a/include/sta/ParseBus.hh
+++ b/include/sta/ParseBus.hh
@@ -68,7 +68,7 @@ void
 parseBusRange(const char *name,
 	      const char *brkts_left,
 	      const char *brkts_right,
-	      char escape,
+	      const char escape,
 	      // Return values.
 	      char *&bus_name,
 	      int &from,
@@ -77,8 +77,8 @@ parseBusRange(const char *name,
 // Insert escapes before ch1 and ch2 in token.
 const char *
 escapeChars(const char *token,
-	    char ch1,
-	    char ch2,
-	    char escape);
+	    const char ch1,
+	    const char ch2,
+	    const char escape);
 
 } // namespace
diff --git a/network/ParseBus.cc b/network/ParseBus.cc
index 9cbf37cb..95e28ac6 100644
--- a/network/ParseBus.cc
+++ b/network/ParseBus.cc
@@ -49,7 +49,7 @@ void
 parseBusName(const char *name,
 	     const char brkt_left,
 	     const char brkt_right,
-	     char escape,
+	     const char escape,
 	     // Return values.
 	     char *&bus_name,
 	     int &index)
@@ -150,9 +150,9 @@ parseBusRange(const char *name,
 
 const char *
 escapeChars(const char *token,
-	    char ch1,
-	    char ch2,
-	    char escape)
+	    const char ch1,
+	    const char ch2,
+	    const char escape)
 {
   int result_length = 0;
   bool need_escapes = false;