diff --git a/Changes b/Changes
index 869d015ab..e5c1ca47c 100644
--- a/Changes
+++ b/Changes
@@ -5,6 +5,8 @@ The contributors that suggested a given feature are shown in []. Thanks!
 
 * Verilator 4.027 devel
 
+****  Add error on misused define. [Topa Tota]
+
 
 * Verilator 4.026 2020-01-11
 
diff --git a/src/V3PreLex.l b/src/V3PreLex.l
index b827e19f8..afd2329f7 100644
--- a/src/V3PreLex.l
+++ b/src/V3PreLex.l
@@ -244,6 +244,11 @@ bom             [\357\273\277]
                           // Note paren level 0 means before "(" of starting args
                           // Level 1 means "," between arguments
                           // Level 2+ means one inside the () of an argument
+                          if (LEXP->m_parenLevel == 1) {  // Starting (
+                              if (!VString::isWhitespace(LEXP->m_defValue)) {
+                                  yyerrorf("Illegal text before '(' that starts define arguments");
+                              }
+                          }
                           if (LEXP->m_parenLevel>1) {
                               appendDefValue(yytext, yyleng); FL_BRK;
                           } else {
diff --git a/src/V3String.cpp b/src/V3String.cpp
index 9c2849872..0a4bba3c8 100644
--- a/src/V3String.cpp
+++ b/src/V3String.cpp
@@ -114,6 +114,13 @@ string VString::spaceUnprintable(const string& str) {
     return out;
 }
 
+bool VString::isWhitespace(const string& str) {
+    for (string::const_iterator pos = str.begin(); pos != str.end(); ++pos) {
+        if (!isspace(*pos)) return false;
+    }
+    return true;
+}
+
 //######################################################################
 // VHashSha256
 
diff --git a/src/V3String.h b/src/V3String.h
index fc20a418a..e473b2b77 100644
--- a/src/V3String.h
+++ b/src/V3String.h
@@ -74,6 +74,8 @@ public:
     // Replace any unprintable with space
     // This includes removing tabs, so column tracking is correct
     static string spaceUnprintable(const string& str);
+    // Return true if only whitespace or ""
+    static bool isWhitespace(const string& str);
 };
 
 //######################################################################
diff --git a/test_regress/t/t_pp_defparen_bad.out b/test_regress/t/t_pp_defparen_bad.out
new file mode 100644
index 000000000..58bbefbb8
--- /dev/null
+++ b/test_regress/t/t_pp_defparen_bad.out
@@ -0,0 +1,7 @@
+%Error: t/t_pp_defparen_bad.v:9: Illegal text before '(' that starts define arguments
+ ( 1,2)
+ ^
+%Error: t/t_pp_defparen_bad.v:9: syntax error, unexpected '('
+((val  1) + (2))
+ ^
+%Error: Exiting due to
diff --git a/test_regress/t/t_pp_defparen_bad.pl b/test_regress/t/t_pp_defparen_bad.pl
new file mode 100755
index 000000000..18439afa9
--- /dev/null
+++ b/test_regress/t/t_pp_defparen_bad.pl
@@ -0,0 +1,19 @@
+#!/usr/bin/perl
+if (!$::Driver) { use FindBin; exec("$FindBin::Bin/bootstrap.pl", @ARGV, $0); die; }
+# DESCRIPTION: Verilator: Verilog Test driver/expect definition
+#
+# Copyright 2003 by Wilson Snyder. This program is free software; you can
+# redistribute it and/or modify it under the terms of either the GNU
+# Lesser General Public License Version 3 or the Perl Artistic License
+# Version 2.0.
+
+scenarios(vlt => 1);
+
+lint(
+    verilator_flags2 => ["-Wpedantic"],
+    fails => 1,
+    expect_filename => $Self->{golden_filename},
+    );
+
+ok(1);
+1;
diff --git a/test_regress/t/t_pp_defparen_bad.v b/test_regress/t/t_pp_defparen_bad.v
new file mode 100644
index 000000000..232d54dbc
--- /dev/null
+++ b/test_regress/t/t_pp_defparen_bad.v
@@ -0,0 +1,9 @@
+// DESCRIPTION: Verilator: Verilog Test module
+//
+// This file ONLY is placed into the Public Domain, for any use,
+// without warranty, 2020 by Wilson Snyder.
+
+`define test(a1,a2) ((a1) + (a2))
+
+`test val
+ ( 1,2)