diff --git a/Changes b/Changes
index f8540fb54..a62177081 100644
--- a/Changes
+++ b/Changes
@@ -49,6 +49,7 @@ Verilator 5.037 devel
 * Fix missing FreeBSD include (#6027) (#6028). [Joel Bodenmann]
 * Fix associative arrays with enum keys (#6034) (#6035). [Petr Nohavica]
 * Fix GCC 10 read-only linker error (#6040). [Todd Strader]
+* Fix WIDTHCONCAT on packed pattern assignment (#6045). [Dan Petrisko]
 * Fix V3OrderParallel scoring contraction hang (#6052). [Bartłomiej Chmiel, Antmicro Ltd.]
 
 
diff --git a/src/V3Width.cpp b/src/V3Width.cpp
index 88f510db1..c1eecc786 100644
--- a/src/V3Width.cpp
+++ b/src/V3Width.cpp
@@ -4722,6 +4722,9 @@ class WidthVisitor final : public VNVisitor {
                 newp = valuep;
             } else {
                 AstConcat* const concatp = new AstConcat{patp->fileline(), newp, valuep};
+                // Have resolved widths, no reason to warn about widths on the concat itself
+                newp->fileline()->modifyWarnOff(V3ErrorCode::WIDTHCONCAT, true);
+                valuep->fileline()->modifyWarnOff(V3ErrorCode::WIDTHCONCAT, true);
                 newp = concatp;
                 newp->dtypeSetLogicSized(concatp->lhsp()->width() + concatp->rhsp()->width(),
                                          nodep->dtypep()->numeric());
diff --git a/test_regress/t/t_lint_width_arraydecl.v b/test_regress/t/t_lint_width_arraydecl.v
index 5de0ecc50..55a3d0e4c 100644
--- a/test_regress/t/t_lint_width_arraydecl.v
+++ b/test_regress/t/t_lint_width_arraydecl.v
@@ -14,8 +14,32 @@ module t(
          input [UADDR_WIDTH-1:0] mAddr,
          output logic [UROM_WIDTH-1:0] mOutput);
 
+   // Issue #3959
    reg [UROM_WIDTH-1:0] uRam[UROM_DEPTH];
 
    always @(posedge clk) mOutput <= uRam[mAddr];
 
+   // Issue #6045
+   typedef enum logic [1:0] { e_0, e_1, e_2, e_3 } enum_e;
+
+   typedef struct packed {
+      integer unsigned x;
+      integer unsigned y;
+   } foo_s;
+
+   typedef struct packed {
+      integer unsigned y;
+   } bar_s;
+
+   // Warning due to concatenation, but this is actually a member assignment
+   localparam foo_s foo = '{
+      y: (1 << e_0) | (1 << e_3)
+      , default: '0
+   };
+
+   // No warning
+   localparam bar_s bar = '{
+      y: (1 << e_0) | (1 << e_3)
+   };
+
 endmodule