diff --git a/ivtest/ivltests/sv_type_identifier_parameter_decl_name.v b/ivtest/ivltests/sv_type_identifier_parameter_decl_name.v
new file mode 100644
index 000000000..f303cfcf1
--- /dev/null
+++ b/ivtest/ivltests/sv_type_identifier_parameter_decl_name.v
@@ -0,0 +1,35 @@
+// Check that parameter declaration names can shadow visible type identifiers.
+
+typedef int L;
+typedef int P;
+typedef int Q;
+typedef int R;
+
+module test;
+
+  reg failed;
+
+  parameter P = 7, R = 13;
+  localparam Q = 11, L = 17;
+
+  `define check(value, expected, error) \
+    if ((value) !== (expected)) begin \
+      $display("FAILED(%0d). %s", `__LINE__, error); \
+      $display("  expected %0h, got %0h", expected, value); \
+      failed = 1'b1; \
+    end
+
+  initial begin
+    failed = 1'b0;
+
+    `check(P, 7, "parameter name did not hide typedef");
+    `check(R, 13, "parameter list continuation did not hide typedef");
+    `check(Q, 11, "localparam name did not hide typedef");
+    `check(L, 17, "localparam list continuation did not hide typedef");
+
+    if (!failed) begin
+      $display("PASSED");
+    end
+  end
+
+endmodule
diff --git a/ivtest/ivltests/sv_type_identifier_parameter_port_name.v b/ivtest/ivltests/sv_type_identifier_parameter_port_name.v
new file mode 100644
index 000000000..76429bebd
--- /dev/null
+++ b/ivtest/ivltests/sv_type_identifier_parameter_port_name.v
@@ -0,0 +1,85 @@
+// Check that parameter port declaration names can shadow visible type identifiers.
+
+typedef int P;
+typedef int Q;
+typedef int R;
+typedef logic [7:0] T;
+typedef int TP;
+
+package p;
+  typedef logic [5:0] PT;
+endpackage
+
+`define check(value, expected, error) \
+  if ((value) !== (expected)) begin \
+    $display("FAILED(%0d). %s", `__LINE__, error); \
+    $display("  expected %0h, got %0h", expected, value); \
+    failed = 1'b1; \
+  end
+
+module M #(
+  parameter int P = 5,
+  Q = 9,
+  int R = 13,
+  T typed_value = 8'ha5,
+  T T = 8'h3c,
+  p::PT pkg_value = 6'h2a,
+  parameter type TP = logic [5:0]
+) (output reg failed);
+
+  TP type_param_value;
+
+  initial begin
+    failed = 1'b0;
+    type_param_value = 6'h15;
+
+    `check(P, 5, "parameter port typed value mismatch");
+    `check(Q, 9, "parameter port untyped continuation mismatch");
+    `check(R, 13, "parameter port atomic type continuation mismatch");
+    `check($bits(typed_value), 8, "parameter port typedef type continuation width mismatch");
+    `check(typed_value, 8'ha5, "parameter port typedef type continuation value mismatch");
+    `check($bits(T), 8, "parameter port type-name continuation did not keep typedef type");
+    `check(T, 8'h3c, "parameter port type-name continuation value mismatch");
+    `check($bits(pkg_value), 6, "parameter port package type continuation width mismatch");
+    `check(pkg_value, 6'h2a, "parameter port package type continuation value mismatch");
+    `check($bits(type_param_value), 6, "parameter port type parameter mismatch");
+    `check(type_param_value, 6'h15, "parameter port type parameter value mismatch");
+  end
+
+endmodule
+
+module N #(P = 3, T typed_value = 8'h5a) (output reg failed);
+
+  initial begin
+    failed = 1'b0;
+
+    `check(P, 3, "omitted parameter keyword mismatch");
+    `check($bits(typed_value), 8, "omitted parameter keyword typedef width mismatch");
+    `check(typed_value, 8'h5a, "omitted parameter keyword typedef value mismatch");
+  end
+
+endmodule
+
+module test;
+
+  reg failed;
+  wire failed_m;
+  wire failed_n;
+
+  M i_m(failed_m);
+  N i_n(failed_n);
+
+  initial begin
+    failed = 1'b0;
+
+    #1;
+
+    `check(failed_m, 1'b0, "parameter port module failed");
+    `check(failed_n, 1'b0, "omitted parameter keyword module failed");
+
+    if (!failed) begin
+      $display("PASSED");
+    end
+  end
+
+endmodule
diff --git a/ivtest/ivltests/sv_type_identifier_parameter_type_decl_name.v b/ivtest/ivltests/sv_type_identifier_parameter_type_decl_name.v
new file mode 100644
index 000000000..857dff533
--- /dev/null
+++ b/ivtest/ivltests/sv_type_identifier_parameter_type_decl_name.v
@@ -0,0 +1,41 @@
+// Check that typed parameter declaration names can shadow visible type identifiers.
+
+typedef int P;
+typedef logic [7:0] T;
+typedef logic [6:0] U;
+
+module test;
+
+  reg failed;
+
+  parameter int P = 13;
+  parameter T typed_value = 8'ha5;
+  parameter T T = 8'h3c;
+  parameter U u0 = 7'h2a, U = 7'h15;
+
+  `define check(value, expected, error) \
+    if ((value) !== (expected)) begin \
+      $display("FAILED(%0d). %s", `__LINE__, error); \
+      $display("  expected %0h, got %0h", expected, value); \
+      failed = 1'b1; \
+    end
+
+  initial begin
+    failed = 1'b0;
+
+    `check(P, 13, "typed parameter name did not hide typedef");
+    `check($bits(typed_value), 8, "typed parameter width mismatch");
+    `check(typed_value, 8'ha5, "typed parameter value mismatch");
+    `check($bits(T), 8, "type-name parameter did not keep typedef type");
+    `check(T, 8'h3c, "type-name parameter value mismatch");
+    `check($bits(u0), 7, "parameter list first declaration did not keep typedef type");
+    `check(u0, 7'h2a, "parameter list first value mismatch");
+    `check($bits(U), 7, "parameter list continuation did not allow typedef name as parameter name");
+    `check(U, 7'h15, "parameter list continuation value mismatch");
+
+    if (!failed) begin
+      $display("PASSED");
+    end
+  end
+
+endmodule
diff --git a/ivtest/ivltests/sv_type_identifier_parameter_type_param_name.v b/ivtest/ivltests/sv_type_identifier_parameter_type_param_name.v
new file mode 100644
index 000000000..2494d7b48
--- /dev/null
+++ b/ivtest/ivltests/sv_type_identifier_parameter_type_param_name.v
@@ -0,0 +1,32 @@
+// Check that type parameter declaration names can shadow visible type identifiers.
+
+typedef int TP;
+
+module test;
+
+  reg failed;
+
+  parameter type TP = logic [3:0];
+
+  TP type_param_value;
+
+  `define check(value, expected, error) \
+    if ((value) !== (expected)) begin \
+      $display("FAILED(%0d). %s", `__LINE__, error); \
+      $display("  expected %0h, got %0h", expected, value); \
+      failed = 1'b1; \
+    end
+
+  initial begin
+    failed = 1'b0;
+    type_param_value = 4'hc;
+
+    `check($bits(type_param_value), 4, "type parameter name did not hide typedef");
+    `check(type_param_value, 4'hc, "type parameter value mismatch");
+
+    if (!failed) begin
+      $display("PASSED");
+    end
+  end
+
+endmodule
diff --git a/ivtest/regress-vvp.list b/ivtest/regress-vvp.list
index c023763ad..b7bf85cc5 100644
--- a/ivtest/regress-vvp.list
+++ b/ivtest/regress-vvp.list
@@ -392,6 +392,10 @@ sv_type_identifier_modport_name	vvp_tests/sv_type_identifier_modport_name.json
 sv_type_identifier_module_name	vvp_tests/sv_type_identifier_module_name.json
 sv_type_identifier_net_name	vvp_tests/sv_type_identifier_net_name.json
 sv_type_identifier_package_item	vvp_tests/sv_type_identifier_package_item.json
+sv_type_identifier_parameter_decl_name	vvp_tests/sv_type_identifier_parameter_decl_name.json
+sv_type_identifier_parameter_port_name	vvp_tests/sv_type_identifier_parameter_port_name.json
+sv_type_identifier_parameter_type_decl_name	vvp_tests/sv_type_identifier_parameter_type_decl_name.json
+sv_type_identifier_parameter_type_param_name	vvp_tests/sv_type_identifier_parameter_type_param_name.json
 sv_type_identifier_port_name	vvp_tests/sv_type_identifier_port_name.json
 sv_type_identifier_specparam_name	vvp_tests/sv_type_identifier_specparam_name.json
 sv_type_identifier_task_function_argument_name	vvp_tests/sv_type_identifier_task_function_argument_name.json
diff --git a/ivtest/vvp_tests/sv_type_identifier_parameter_decl_name.json b/ivtest/vvp_tests/sv_type_identifier_parameter_decl_name.json
new file mode 100644
index 000000000..9f265426c
--- /dev/null
+++ b/ivtest/vvp_tests/sv_type_identifier_parameter_decl_name.json
@@ -0,0 +1,5 @@
+{
+    "type"          : "normal",
+    "source"        : "sv_type_identifier_parameter_decl_name.v",
+    "iverilog-args" : [ "-g2005-sv" ]
+}
diff --git a/ivtest/vvp_tests/sv_type_identifier_parameter_port_name.json b/ivtest/vvp_tests/sv_type_identifier_parameter_port_name.json
new file mode 100644
index 000000000..91cf1e3aa
--- /dev/null
+++ b/ivtest/vvp_tests/sv_type_identifier_parameter_port_name.json
@@ -0,0 +1,5 @@
+{
+    "type"          : "normal",
+    "source"        : "sv_type_identifier_parameter_port_name.v",
+    "iverilog-args" : [ "-g2005-sv" ]
+}
diff --git a/ivtest/vvp_tests/sv_type_identifier_parameter_type_decl_name.json b/ivtest/vvp_tests/sv_type_identifier_parameter_type_decl_name.json
new file mode 100644
index 000000000..d51f1988e
--- /dev/null
+++ b/ivtest/vvp_tests/sv_type_identifier_parameter_type_decl_name.json
@@ -0,0 +1,5 @@
+{
+    "type"          : "normal",
+    "source"        : "sv_type_identifier_parameter_type_decl_name.v",
+    "iverilog-args" : [ "-g2005-sv" ]
+}
diff --git a/ivtest/vvp_tests/sv_type_identifier_parameter_type_param_name.json b/ivtest/vvp_tests/sv_type_identifier_parameter_type_param_name.json
new file mode 100644
index 000000000..fe48a962a
--- /dev/null
+++ b/ivtest/vvp_tests/sv_type_identifier_parameter_type_param_name.json
@@ -0,0 +1,5 @@
+{
+    "type"          : "normal",
+    "source"        : "sv_type_identifier_parameter_type_param_name.v",
+    "iverilog-args" : [ "-g2005-sv" ]
+}
diff --git a/parse.y b/parse.y
index 35e6c89fb..0803658e8 100644
--- a/parse.y
+++ b/parse.y
@@ -139,12 +139,16 @@ static data_type_t *pform_make_parray_type(const struct vlltype&loc,
 
 template <class T>
 static void set_type_id_range(T&value, data_type_t *type, char *id,
-			      unsigned lexical_pos,
+			      const YYLTYPE&loc,
 			      std::list<pform_range_t> *ranges)
 {
       value.type = type;
       value.id = id;
-      value.lexical_pos = lexical_pos;
+      value.lexical_pos = loc.lexical_pos;
+      value.first_line = loc.first_line;
+      value.first_column = loc.first_column;
+      value.last_line = loc.last_line;
+      value.last_column = loc.last_column;
       value.ranges = ranges;
 }
 
@@ -299,6 +303,29 @@ static decl_assignment_t *pform_make_net_decl(const YYLTYPE&loc, char *id,
       return pform_make_net_decl(loc, id, loc.lexical_pos, udims, init);
 }
 
+static void pform_set_parameter(const YYLTYPE&loc, char *id, unsigned lexical_pos,
+				bool is_local, bool is_type,
+				type_restrict_t type_restrict,
+				data_type_t*data_type, const list<pform_range_t>*udims,
+				PExpr*expr, LexicalScope::range_t*value_range)
+{
+      YYLTYPE id_loc = loc;
+      id_loc.lexical_pos = lexical_pos;
+      pform_set_parameter(id_loc, lex_strings.make(id), is_local, is_type,
+			  type_restrict, data_type, udims, expr, value_range);
+      delete[] id;
+}
+
+static void pform_set_parameter(const YYLTYPE&loc, char *id,
+				bool is_local, bool is_type,
+				type_restrict_t type_restrict,
+				data_type_t*data_type, const list<pform_range_t>*udims,
+				PExpr*expr, LexicalScope::range_t*value_range)
+{
+      pform_set_parameter(loc, id, loc.lexical_pos, is_local, is_type,
+			  type_restrict, data_type, udims, expr, value_range);
+}
+
 template <class T> void append(vector<T>&out, const std::vector<T>&in)
 {
       for (size_t idx = 0 ; idx < in.size() ; idx += 1)
@@ -699,6 +726,10 @@ Module::port_t *module_declare_interface_port(const YYLTYPE&loc, char *type,
 	    data_type_t *type;
 	    char *id;
 	    unsigned lexical_pos;
+	    int first_line;
+	    int first_column;
+	    int last_line;
+	    int last_column;
 	    std::list<pform_range_t>*ranges;
       } type_id_range;
 
@@ -2721,25 +2752,26 @@ tf_port_declaration /* IEEE1800-2005: A.2.7 */
   // dimensions followed by a separate declaration name.
 data_type_or_implicit_plus_id_base
   : IDENTIFIER
-      { set_type_id_range($$, nullptr, $1, @1.lexical_pos, nullptr);
+      { set_type_id_range($$, nullptr, $1, @1, nullptr);
       }
   | atomic_type identifier_name
-      { set_type_id_range($$, $1, $2, @2.lexical_pos, nullptr);
+      { set_type_id_range($$, $1, $2, @2, nullptr);
       }
   | implicit_type identifier_name
-      { set_type_id_range($$, $1, $2, @2.lexical_pos, nullptr);
+      { set_type_id_range($$, $1, $2, @2, nullptr);
       }
   | ps_type_identifier_dim identifier_name
-      { set_type_id_range($$, $1, $2, @2.lexical_pos, nullptr);
+      { set_type_id_range($$, $1, $2, @2, nullptr);
       }
   ;
 
 data_type_or_implicit_plus_id_dim
   : TYPE_IDENTIFIER dimensions_opt
-      { set_type_id_range($$, nullptr, $1.text, @1.lexical_pos, $2);
+      { set_type_id_range($$, nullptr, $1.text, @1, $2);
       }
   | data_type_or_implicit_plus_id_base dimensions_opt
-      { set_type_id_range($$, $1.type, $1.id, $1.lexical_pos, $2);
+      { $$ = $1;
+	$$.ranges = $2;
       }
   ;
 
@@ -2749,19 +2781,19 @@ data_type_or_implicit_plus_id_dim
   // still parsed as a continuation of the previous port declaration.
 partial_port_type_plus_id_dim
   : atomic_type identifier_name dimensions_opt
-      { set_type_id_range($$, $1, $2, @2.lexical_pos, $3);
+      { set_type_id_range($$, $1, $2, @2, $3);
       }
   | implicit_type identifier_name dimensions_opt
-      { set_type_id_range($$, $1, $2, @2.lexical_pos, $3);
+      { set_type_id_range($$, $1, $2, @2, $3);
       }
   ;
 
 partial_port_name_dim
   : IDENTIFIER dimensions_opt
-      { set_type_id_range($$, nullptr, $1, @1.lexical_pos, $2);
+      { set_type_id_range($$, nullptr, $1, @1, $2);
       }
   | TYPE_IDENTIFIER dimensions_opt
-      { set_type_id_range($$, nullptr, $1.text, @1.lexical_pos, $2);
+      { set_type_id_range($$, nullptr, $1.text, @1, $2);
       }
   ;
 
@@ -2772,7 +2804,7 @@ partial_port_typedef_plus_id_dim
 	FILE_NAME(tmp, @1);
 	delete[]$1.text;
 	tmp = pform_make_parray_type(@2, tmp, $2);
-	set_type_id_range($$, tmp, $3, @3.lexical_pos, $4);
+	set_type_id_range($$, tmp, $3, @3, $4);
       }
   | package_scope TYPE_IDENTIFIER dimensions_opt identifier_name dimensions_opt
       { lex_in_package_scope(nullptr);
@@ -2780,7 +2812,7 @@ partial_port_typedef_plus_id_dim
 	FILE_NAME(tmp, @2);
 	delete[]$2.text;
 	tmp = pform_make_parray_type(@3, tmp, $3);
-	set_type_id_range($$, tmp, $4, @4.lexical_pos, $5);
+	set_type_id_range($$, tmp, $4, @4, $5);
       }
   ;
 
@@ -5202,38 +5234,27 @@ type_param
   ;
 
 module_parameter
-  : parameter param_type parameter_assign
-  | localparam param_type parameter_assign
+  : parameter parameter_assign_with_type
+  | localparam parameter_assign_with_type
       { pform_requires_sv(@1, "Local parameter in module parameter port list");
       }
   ;
 
 module_parameter_port_list
   : module_parameter
-  | data_type_opt
-      { param_data_type = $1;
-        param_is_local = false;
-        param_is_type = false;
-	param_type_restrict = {};
-      }
-    parameter_assign
-      { pform_requires_sv(@3, "Omitting initial `parameter` in parameter port "
+  | value_parameter_assign_with_type
+      { pform_requires_sv(@1, "Omitting initial `parameter` in parameter port "
 			      "list");
       }
   | type_param
       { param_is_local = false; }
     parameter_assign
   | module_parameter_port_list ',' module_parameter
-  | module_parameter_port_list ',' data_type_opt
-      { if ($3) {
-	      pform_requires_sv(@3, "Omitting `parameter`/`localparam` before "
-				    "data type in parameter port list");
-	      param_data_type = $3;
-	      param_is_type = false;
-	      param_type_restrict = {};
-        }
+  | module_parameter_port_list ',' parameter_assign
+  | module_parameter_port_list ',' value_parameter_assign_with_explicit_type
+      { pform_requires_sv(@3, "Omitting `parameter`/`localparam` before "
+			      "data type in parameter port list");
       }
-    parameter_assign
   | module_parameter_port_list ',' type_param parameter_assign
   ;
 
@@ -5847,19 +5868,6 @@ net_type_or_var_opt
   | K_var        { $$ = NetNet::REG; }
   ;
 
-  /* The param_type rule is just the data_type_or_implicit rule wrapped
-     with an assignment to para_data_type with the figured data type.
-     This is used by parameter_assign, which is found to the right of
-     the param_type in various rules. */
-
-param_type
-  : data_type_or_implicit
-      { param_is_type = false;
-        param_data_type = $1;
-	param_type_restrict = {};
-      }
-  | type_param
-
 parameter
   : K_parameter
       { param_is_local = false; }
@@ -5871,7 +5879,7 @@ localparam
   ;
 
 parameter_declaration
-  : parameter_or_localparam param_type parameter_assign_list ';'
+  : parameter_or_localparam parameter_assign_list_with_type ';'
 
 parameter_or_localparam
   : parameter
@@ -5883,17 +5891,73 @@ parameter_or_localparam
      handling code. localparams parse the same as parameters, they
      just behave differently when someone tries to override them. */
 
-parameter_assign_list
-  : parameter_assign
-  | parameter_assign_list ',' parameter_assign
+  // The first parameter assignment is parsed together with the optional type
+  // so `parameter T` can shadow a typedef name, while `parameter T p` still
+  // parses T as the parameter type. Continuations keep the previous type, so a
+  // bare typedef name after a comma is still a parameter name.
+parameter_assign_list_with_type
+  : parameter_assign_with_type
+  | parameter_assign_list_with_type ',' parameter_assign
+  ;
+
+parameter_assign_with_type
+  : value_parameter_assign_with_type
+  | type_param parameter_assign
+  ;
+
+value_parameter_assign_with_type
+  : data_type_or_implicit_plus_id_dim initializer_opt parameter_value_ranges_opt
+      { param_is_type = false;
+	param_type_restrict = {};
+	param_data_type = $1.type;
+	YYLTYPE id_loc = @1;
+	id_loc.first_line = $1.first_line;
+	id_loc.first_column = $1.first_column;
+	id_loc.last_line = $1.last_line;
+	id_loc.last_column = $1.last_column;
+	id_loc.lexical_pos = $1.lexical_pos;
+	pform_set_parameter(id_loc, $1.id, param_is_local,
+			    param_is_type, param_type_restrict,
+			    param_data_type, $1.ranges, $2, $3);
+      }
+  ;
+
+  // Parameter port lists allow an explicit type after a comma without
+  // repeating `parameter`, e.g. `#(parameter p = 1, int q = 2)`. Keep this
+  // narrower than value_parameter_assign_with_type so a bare typedef name
+  // after a comma remains a parameter name that inherits the previous type.
+value_parameter_assign_with_explicit_type
+  : atomic_type identifier_name dimensions_opt initializer_opt parameter_value_ranges_opt
+      { param_is_type = false;
+	param_type_restrict = {};
+	param_data_type = $1;
+	pform_set_parameter(@2, $2, param_is_local,
+			    param_is_type, param_type_restrict,
+			    param_data_type, $3, $4, $5);
+      }
+  | implicit_type identifier_name dimensions_opt initializer_opt parameter_value_ranges_opt
+      { param_is_type = false;
+	param_type_restrict = {};
+	param_data_type = $1;
+	pform_set_parameter(@2, $2, param_is_local,
+			    param_is_type, param_type_restrict,
+			    param_data_type, $3, $4, $5);
+      }
+  | ps_type_identifier_dim identifier_name dimensions_opt initializer_opt parameter_value_ranges_opt
+      { param_is_type = false;
+	param_type_restrict = {};
+	param_data_type = $1;
+	pform_set_parameter(@2, $2, param_is_local,
+			    param_is_type, param_type_restrict,
+			    param_data_type, $3, $4, $5);
+      }
   ;
 
 parameter_assign
-  : IDENTIFIER dimensions_opt initializer_opt parameter_value_ranges_opt
-      { pform_set_parameter(@1, lex_strings.make($1), param_is_local,
+  : identifier_name dimensions_opt initializer_opt parameter_value_ranges_opt
+      { pform_set_parameter(@1, $1, param_is_local,
 			    param_is_type, param_type_restrict,
 			    param_data_type, $2, $3, $4);
-	delete[]$1;
       }
   ;