diff --git a/ivtest/ivltests/br_gh1237.v b/ivtest/ivltests/br_gh1237.v
new file mode 100644
index 000000000..52889e1cc
--- /dev/null
+++ b/ivtest/ivltests/br_gh1237.v
@@ -0,0 +1,30 @@
+// The ternary operator should cause the 'in' variable to be unsigned extended.
+module test;
+  reg passed;
+  reg [7:0] res;
+  reg signed in;
+
+  initial begin
+    passed = 1'b1;
+    in = 1;
+    $display("in4: %0d", in);
+
+    res = 0 ? 1'h0 : in;
+    $display("T0 = %d, %d", 0 ? 1'h0 : in, res); // These work
+    case (0 ? 1'h0 : in) // But this fails
+      5'b0101: begin $display("FAILED: T0 matched 5'b0101"); passed = 1'b0;end
+      8'b000001: begin $display("T0 matched 8'b000001"); end
+      default: begin $display("FAILED: T0 matched default"); passed = 1'b0;end
+    endcase
+
+    res = 1 ? in : 1'h0;
+    $display("T1 = %d, %d", 1 ? in : 1'h0, res); // These work
+    case (1 ? in : 1'h0) // But this fails
+      5'b0101: begin $display("FAILED: T1 matched 5'b0101"); passed = 1'b0;end
+      8'b000001: begin $display("T1 matched 8'b000001"); end
+      default: begin $display("FAILED: T1 matched default"); passed = 1'b0;end
+    endcase
+
+    if (passed) $display("PASSED");
+  end
+endmodule
diff --git a/ivtest/regress-vlg.list b/ivtest/regress-vlg.list
index 54d54ed92..5a9c6aa33 100644
--- a/ivtest/regress-vlg.list
+++ b/ivtest/regress-vlg.list
@@ -370,6 +370,7 @@ br_gh1223c		normal,-g2009		ivltests
 br_gh1225a		CE			ivltests gold=br_gh1225a.gold
 br_gh1225b		CE			ivltests gold=br_gh1225b.gold
 br_gh1225c		CE			ivltests gold=br_gh1225c.gold
+br_gh1237		normal			ivltests
 br_ml20150315		normal			ivltests gold=br_ml_20150315.gold
 br_ml20150321		CE			ivltests
 br_mw20171108		normal			ivltests
diff --git a/ivtest/regress-vlog95.list b/ivtest/regress-vlog95.list
index b8289cbfc..05a8b8388 100644
--- a/ivtest/regress-vlog95.list
+++ b/ivtest/regress-vlog95.list
@@ -862,6 +862,7 @@ br_gh793		normal,-pallowsigned=1	ivltests
 br_gh1223a		normal,-g2009,-pallowsigned=1   ivltests
 br_gh1223b		normal,-g2009,-pallowsigned=1   ivltests
 br_gh1223c		normal,-g2009,-pallowsigned=1   ivltests
+br_gh1237		normal,-pallowsigned=1  ivltests
 ca_mult			normal,-pallowsigned=1	ivltests gold=ca_mult.gold
 cast_int		normal,-pallowsigned=1	ivltests
 cfunc_assign_op_vec	normal,-g2009,-pallowsigned=1	ivltests
diff --git a/net_proc.cc b/net_proc.cc
index ad2644b40..fe4ab5a8f 100644
--- a/net_proc.cc
+++ b/net_proc.cc
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2000-2021 Stephen Williams (steve@icarus.com)
+ * Copyright (c) 2000-2025 Stephen Williams (steve@icarus.com)
  *
  *    This source code is free software; you can redistribute it
  *    and/or modify it in source code form under the terms of the GNU
@@ -154,7 +154,8 @@ void NetCase::prune()
       }
 
 	// Prune the case expression
-      expr_ = pad_to_width(unpadded_expr->dup_expr(), prune_width, *expr_);
+      expr_ = pad_to_width(unpadded_expr->dup_expr(), prune_width,
+                           padded_expr->has_sign(), *expr_);
       delete padded_expr;
 
 	// Prune the case item expressions