diff --git a/src/V3ParseImp.cpp b/src/V3ParseImp.cpp
index 9c7fe7df1..4d705e1cf 100644
--- a/src/V3ParseImp.cpp
+++ b/src/V3ParseImp.cpp
@@ -330,6 +330,10 @@ void V3ParseImp::lexFile(const string& modname) {
     if (bisonParse()) v3fatal("Cannot continue\n");
 }
 
+bool V3ParseImp::bisonValIdThenColon() const {
+    return bisonValPrev().token == yaID__ETC && bisonValCur().token == yP_COLONCOLON;
+}
+
 void V3ParseImp::lexToken() {
     // called from lexToBison, has a "this"
     // Fetch next token from prefetch or real lexer
@@ -476,8 +480,8 @@ void V3ParseImp::lexToken() {
 int V3ParseImp::lexToBison() {
     // Called as global since bison doesn't have our pointer
     lexToken();  // sets yylval
-    m_prevBisonVal = m_curBisonVal;
-    m_curBisonVal = yylval;
+    m_bisonValPrev = m_bisonValCur;
+    m_bisonValCur = yylval;
 
     // yylval.scp = NULL;   // Symbol table not yet needed - no packages
     if (debugFlex() >= 6 || debugBison() >= 6) {  // --debugi-flex and --debugi-bison
diff --git a/src/V3ParseImp.h b/src/V3ParseImp.h
index cef05f600..26841ba70 100644
--- a/src/V3ParseImp.h
+++ b/src/V3ParseImp.h
@@ -116,8 +116,8 @@ class V3ParseImp {
     int m_prevLexToken;  // previous parsed token (for lexer)
     bool m_ahead;  // aheadval is valid
     V3ParseBisonYYSType m_aheadVal;  // ahead token value
-    V3ParseBisonYYSType m_curBisonVal;  // current token for error reporting
-    V3ParseBisonYYSType m_prevBisonVal;  // previous token for error reporting
+    V3ParseBisonYYSType m_bisonValCur;  // current token for error reporting
+    V3ParseBisonYYSType m_bisonValPrev;  // previous token for error reporting
 
     std::deque<string*> m_stringps;  // Created strings for later cleanup
     std::deque<V3Number*> m_numberps;  // Created numbers for later cleanup
@@ -229,8 +229,9 @@ public:
     static int stateVerilogRecent();  // Parser -> lexer communication
     int prevLexToken() const { return m_prevLexToken; }  // Parser -> lexer communication
     size_t flexPpInputToLex(char* buf, size_t max_size) { return ppInputToLex(buf, max_size); }
-    V3ParseBisonYYSType curBisonVal() const { return m_curBisonVal; }
-    V3ParseBisonYYSType prevBisonVal() const { return m_prevBisonVal; }
+    V3ParseBisonYYSType bisonValCur() const { return m_bisonValCur; }
+    V3ParseBisonYYSType bisonValPrev() const { return m_bisonValPrev; }
+    bool bisonValIdThenColon() const;
 
     //==== Symbol tables
     V3ParseSym* symp() { return m_symp; }
@@ -249,8 +250,8 @@ public:
         m_lastVerilogState = stateVerilogRecent();
         m_prevLexToken = 0;
         m_ahead = false;
-        m_curBisonVal.token = 0;
-        m_prevBisonVal.token = 0;
+        m_bisonValCur.token = 0;
+        m_bisonValPrev.token = 0;
         // m_aheadVal not used as m_ahead = false, and not all compilers support initing it
         m_tagNodep = NULL;
         m_timeLastUnit = v3Global.opt.timeDefaultUnit();
diff --git a/src/verilog.l b/src/verilog.l
index 8baf30c9a..b49e67add 100644
--- a/src/verilog.l
+++ b/src/verilog.l
@@ -27,9 +27,6 @@
 #include "V3ParseImp.h"  // Defines YYTYPE; before including bison header
 #include "V3ParseBison.h"  // Generated by bison
 
-extern void yyerror(const char*);
-extern void yyerrorf(const char* format, ...);
-
 #define STATE_VERILOG_RECENT S17  // State name for most recent Verilog Version
 
 #define PARSEP V3ParseImp::parsep()
@@ -61,38 +58,6 @@ extern void yyerrorf(const char* format, ...);
 
 //======================================================================
 
-void yyerror(const char* errmsg) {
-    PARSEP->fileline()->v3error(errmsg);
-    static const char* const colonmsg = "syntax error, unexpected ::, ";
-    // tokens;
-    if (0 == strncmp(errmsg, colonmsg, strlen(colonmsg))
-        && PARSEP->prevBisonVal().token == yaID__ETC
-        && PARSEP->curBisonVal().token == yP_COLONCOLON) {
-        static int warned = false;
-        if (!warned++) {
-            std::cerr << PARSEP->fileline()->warnMore()
-                      << ("... Perhaps '" + *PARSEP->prevBisonVal().strp
-                          + "' is a package which needs to be predeclared? (IEEE 1800-2017 26.3)")
-                      << std::endl;
-        }
-    }
-}
-
-void yyerrorf(const char* format, ...) {
-    const int maxlen = 2000;
-    char msg[maxlen];
-
-    va_list ap;
-    va_start(ap, format);
-    VL_VSNPRINTF(msg, maxlen, format, ap);
-    msg[maxlen - 1] = '\0';
-    va_end(ap);
-
-    yyerror(msg);
-}
-
-//======================================================================
-
 static double lexParseDouble(FileLine* fl, const char* textp, size_t length) {
     string text = std::string(textp, length);
     bool success = false;
diff --git a/src/verilog.y b/src/verilog.y
index cfaabf39f..df07fb93a 100644
--- a/src/verilog.y
+++ b/src/verilog.y
@@ -44,9 +44,6 @@
 #define GATEUNSUP(fl, tok) \
     { BBUNSUP((fl), "Unsupported: Verilog 1995 gate primitive: " << (tok)); }
 
-extern void yyerror(const char* errmsg);
-extern void yyerrorf(const char* format, ...);
-
 //======================================================================
 // Statics (for here only)
 
@@ -293,6 +290,36 @@ static void UNSUPREAL(FileLine* fileline) {
 
 //======================================================================
 
+void yyerror(const char* errmsg) {
+    PARSEP->fileline()->v3error(errmsg);
+    static const char* const colonmsg = "syntax error, unexpected ::, ";
+    // tokens;
+    if (0 == strncmp(errmsg, colonmsg, strlen(colonmsg)) && PARSEP->bisonValIdThenColon()) {
+        static int warned = false;
+        if (!warned++) {
+            std::cerr << PARSEP->fileline()->warnMore()
+                      << ("... Perhaps '" + *PARSEP->bisonValPrev().strp
+                          + "' is a package which needs to be predeclared? (IEEE 1800-2017 26.3)")
+                      << std::endl;
+        }
+    }
+}
+
+void yyerrorf(const char* format, ...) {
+    const int maxlen = 2000;
+    char msg[maxlen];
+
+    va_list ap;
+    va_start(ap, format);
+    VL_VSNPRINTF(msg, maxlen, format, ap);
+    msg[maxlen - 1] = '\0';
+    va_end(ap);
+
+    yyerror(msg);
+}
+
+//======================================================================
+
 class AstSenTree;
 // clang-format off
 %}