diff --git a/Changes b/Changes
index 58c8272c2..282fd56b5 100644
--- a/Changes
+++ b/Changes
@@ -40,6 +40,8 @@ The contributors that suggested a given feature are shown in []. Thanks!
 
 ****  Fix logical not optimization with empty begin, #2291. [Baltazar Ortiz]
 
+****  Fix reduction OR on wide data, broke in v4.026, #2300. [Jack Koening]
+
 
 * Verilator 4.032 2020-04-04
 
diff --git a/include/verilatedos.h b/include/verilatedos.h
index 352f7f87b..66904c460 100644
--- a/include/verilatedos.h
+++ b/include/verilatedos.h
@@ -363,7 +363,7 @@ typedef unsigned long long vluint64_t;  ///< 64-bit unsigned type
 #define VL_BYTESIZE 8  ///< Bits in a CData / byte
 #define VL_SHORTSIZE 16  ///< Bits in a SData / short
 #define VL_IDATASIZE 32  ///< Bits in a IData / word
-#define VL_WORDSIZE IDATASIZE  ///< Legacy define
+#define VL_WORDSIZE VL_IDATASIZE  ///< Legacy define
 #define VL_QUADSIZE 64  ///< Bits in a QData / quadword
 #define VL_EDATASIZE 32  ///< Bits in a EData (WData entry)
 #define VL_EDATASIZE_LOG2 5  ///< log2(VL_EDATASIZE)
diff --git a/src/V3Expand.cpp b/src/V3Expand.cpp
index cbc2ccfe9..6b33f497f 100644
--- a/src/V3Expand.cpp
+++ b/src/V3Expand.cpp
@@ -796,7 +796,8 @@ private:
             }
             newp = new AstEq(
                 nodep->fileline(),
-                new AstConst(nodep->fileline(), AstConst::SizedEData(), ~VL_MASK_E(0)), newp);
+                new AstConst(nodep->fileline(), AstConst::SizedEData(), VL_MASK_E(VL_EDATASIZE)),
+                newp);
             VL_DO_DANGLING(replaceWithDelete(nodep, newp), nodep);
         } else {
             UINFO(8, "    REDAND->EQ " << nodep << endl);
diff --git a/test_regress/t/t_math_red.pl b/test_regress/t/t_math_red.pl
new file mode 100755
index 000000000..1d046ed3f
--- /dev/null
+++ b/test_regress/t/t_math_red.pl
@@ -0,0 +1,21 @@
+#!/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.
+# SPDX-License-Identifier: LGPL-3.0-only OR Artistic-2.0
+
+scenarios(simulator => 1);
+
+compile(
+    );
+
+execute(
+    check_finished => 1,
+    );
+
+ok(1);
+1;
diff --git a/test_regress/t/t_math_red.v b/test_regress/t/t_math_red.v
new file mode 100644
index 000000000..10cb292b8
--- /dev/null
+++ b/test_regress/t/t_math_red.v
@@ -0,0 +1,65 @@
+// DESCRIPTION: Verilator: Verilog Test module
+//
+// This file ONLY is placed under the Creative Commons Public Domain, for
+// any use, without warranty, 2004 by Wilson Snyder.
+// SPDX-License-Identifier: CC0-1.0
+
+`define checkh(gotv,expv) do if ((gotv) !== (expv)) begin $write("%%Error: %s:%0d:  got='h%x exp='h%x\n", `__FILE__,`__LINE__, (gotv), (expv)); $stop; end while(0)
+
+module t (/*AUTOARG*/
+   // Inputs
+   clk
+   );
+
+   input clk;
+   integer cyc; initial cyc=0;
+
+   reg [67:0]    r;
+
+   wire and_reduce = &r;
+   wire or_reduce = |r;
+   wire xor_reduce = ^r;
+   wire xnor_reduce = ~^r;
+   wire check_equal = r == 68'hffff_ffff_ffff_ffff_f;
+
+   always @(posedge clk) begin
+`ifdef TEST_VERBOSE
+      $display("cyc=%0d, r = %x, and_reduce = %x, or=%x xor=%x check_equal = %x",
+               cyc, r, and_reduce, or_reduce, xor_reduce, check_equal);
+`endif
+      cyc <= cyc + 1;
+      if (cyc == 1) begin
+         r <= 68'd0;
+      end
+      else if (cyc == 10) begin
+         `checkh(r, 68'h0000_0000_0000_0000_0);
+         `checkh(and_reduce, '0);
+         `checkh(or_reduce, '0);
+         `checkh(xor_reduce, '0);
+         `checkh(xnor_reduce, '1);
+         r <= 68'hffff_ffff_ffff_ffff_e;
+      end
+      else if (cyc == 11) begin
+         `checkh(r, 68'hffff_ffff_ffff_ffff_e);
+         `checkh(and_reduce, '0);
+         `checkh(or_reduce, '1);
+         `checkh(xor_reduce, '1);
+         `checkh(xnor_reduce, '0);
+         r <= 68'hffff_ffff_ffff_ffff_f;
+      end
+      else if (cyc == 12) begin
+         `checkh(r, 68'hffff_ffff_ffff_ffff_f);
+         `checkh(and_reduce, '1);
+         `checkh(or_reduce, '1);
+         `checkh(xor_reduce, '0);
+         `checkh(xnor_reduce, '1);
+      end
+      else if (cyc == 90) begin
+         $write("*-* All Finished *-*\n");
+         $finish;
+      end
+      else begin
+         r <= 68'd0;
+      end
+   end
+endmodule