diff --git a/Changes b/Changes
index 6662cfff7..2c76dba5e 100644
--- a/Changes
+++ b/Changes
@@ -19,6 +19,7 @@ Verilator 5.031 devel
 * Fix VPI error instead of fatal for vpi_get_value() on large signals (#5571). [Todd Strader]
 * Fix --output-groups leftover files issue (#5574). [Todd Strader]
 * Fix slow unsized number parsing (#5577). [Geza Lore]
+* Fix negative assignment pattern keys (#5580). [Iztok Jeras]
 
 
 Verilator 5.030 2024-10-27
diff --git a/src/verilog.y b/src/verilog.y
index 9fbf16bde..0272e2c4d 100644
--- a/src/verilog.y
+++ b/src/verilog.y
@@ -4006,11 +4006,18 @@ patternKey<nodep>:              // IEEE: merge structure_pattern_key, array_patt
         //                      //   "foo"member (if structure)
         //                      //   So for now we only allow a true constant number, or an
         //                      //   identifier which we treat as a structure member name
-                yaINTNUM                                { $$ = new AstConst{$<fl>1, *$1}; }
-        |       yaFLOATNUM                              { $$ = new AstConst{$<fl>1, AstConst::RealDouble{}, $1}; }
-        |       id                                      { $$ = new AstText{$<fl>1, *$1}; }
-        |       strAsInt                                { $$ = $1; }
-        |       simple_typeNoRef                        { $$ = $1; }
+                yaINTNUM
+                        { $$ = new AstConst{$<fl>1, *$1}; }
+        |       '-' yaINTNUM
+                        { V3Number neg{*$2}; neg.opNegate(*$2); $$ = new AstConst{$<fl>2, neg}; }
+        |       yaFLOATNUM
+                        { $$ = new AstConst{$<fl>1, AstConst::RealDouble{}, $1}; }
+        |       id
+                        { $$ = new AstText{$<fl>1, *$1}; }
+        |       strAsInt
+                        { $$ = $1; }
+        |       simple_typeNoRef
+                        { $$ = $1; }
         //                      // expanded from simple_type ps_type_identifier (part of simple_type)
         //                      // expanded from simple_type ps_parameter_identifier (part of simple_type)
         |       packageClassScopeE idType
diff --git a/test_regress/t/t_array_pattern_2d.v b/test_regress/t/t_array_pattern_2d.v
index dba37eef2..051e1f1d8 100644
--- a/test_regress/t/t_array_pattern_2d.v
+++ b/test_regress/t/t_array_pattern_2d.v
@@ -13,6 +13,8 @@ module t (/*AUTOARG*/);
    logic [31:0] larray_assign [0:3];
    logic [31:0] larray_other [0:3];
 
+   logic [31:0] array_neg [-1:1];
+
    initial begin
       array_assign[0] = 32'd1;
       array_assign[3:1] = '{32'd4, 32'd3, 32'd2};
@@ -34,6 +36,11 @@ module t (/*AUTOARG*/);
       if (larray_other[2] != 3) $stop;
       if (larray_other[3] != 2) $stop;
 
+      array_neg = '{-1: 5, 1: 7, default: 'd6};
+      if (array_neg[-1] != 5) $stop;
+      if (array_neg[0] != 6) $stop;
+      if (array_neg[1] != 7) $stop;
+
       $write("*-* All Finished *-*\n");
       $finish;
    end