diff --git a/doc/AST_FORMAT.md b/doc/AST_FORMAT.md
index 139e4447f..ede684a1f 100644
--- a/doc/AST_FORMAT.md
+++ b/doc/AST_FORMAT.md
@@ -2139,7 +2139,7 @@ Format:
 "in X[^foo bar]"
      ~ begin (const-pattern)
                ~ end (const-pattern)
-     ~~~~~~~~~~~ expression (const-pattern)
+    ~~~~~~~~~~~~ expression (const-pattern)
     ~ name (const-pattern.const)
     ~ expression (const-pattern.const)
 ~~~
@@ -2157,7 +2157,7 @@ Format:
 "in X[foo:, bar:]"
      ~ begin (const-pattern)
                 ~ end (const-pattern)
-     ~~~~~~~~~~~~ expression (const-pattern)
+    ~~~~~~~~~~~~~ expression (const-pattern)
     ~ name (const-pattern.const)
     ~ expression (const-pattern.const)
 ~~~
@@ -2173,7 +2173,7 @@ Format:
 "in X[]"
      ~ begin (const-pattern)
       ~ end (const-pattern)
-     ~~ expression (const-pattern)
+    ~~~ expression (const-pattern)
     ~ name (const-pattern.const)
     ~ expression (const-pattern.const)
      ~~ expression (const-pattern.array_pattern)
diff --git a/lib/parser/builders/default.rb b/lib/parser/builders/default.rb
index 319fda516..860d84e84 100644
--- a/lib/parser/builders/default.rb
+++ b/lib/parser/builders/default.rb
@@ -1340,7 +1340,11 @@ def match_with_trailing_comma(match, comma_t)
 
     def const_pattern(const, ldelim_t, pattern, rdelim_t)
       n(:const_pattern, [const, pattern],
-        collection_map(ldelim_t, [pattern], rdelim_t))
+        Source::Map::Collection.new(
+          loc(ldelim_t), loc(rdelim_t),
+          const.loc.expression.join(loc(rdelim_t))
+        )
+      )
     end
 
     def pin(pin_t, var)
diff --git a/test/test_parser.rb b/test/test_parser.rb
index a2279bae9..884f135f8 100644
--- a/test/test_parser.rb
+++ b/test/test_parser.rb
@@ -8993,7 +8993,7 @@ def test_pattern_matching_const_pattern
         nil,
         s(:true)),
       %q{in A(1, 2) then true},
-      %q{    ~~~~~~ expression (in_pattern.const_pattern)
+      %q{   ~~~~~~~ expression (in_pattern.const_pattern)
         |    ~ begin (in_pattern.const_pattern)
         |         ~ end (in_pattern.const_pattern)
         |   ~ expression (in_pattern.const_pattern.const)
@@ -9009,7 +9009,7 @@ def test_pattern_matching_const_pattern
         nil,
         s(:true)),
       %q{in A(x:) then true},
-      %q{    ~~~~ expression (in_pattern.const_pattern)
+      %q{   ~~~~~ expression (in_pattern.const_pattern)
         |    ~ begin (in_pattern.const_pattern)
         |       ~ end (in_pattern.const_pattern)
         |   ~ expression (in_pattern.const_pattern.const)
@@ -9024,7 +9024,7 @@ def test_pattern_matching_const_pattern
         nil,
         s(:true)),
       %q{in A() then true},
-      %q{    ~~ expression (in_pattern.const_pattern)
+      %q{   ~~~ expression (in_pattern.const_pattern)
         |    ~ begin (in_pattern.const_pattern)
         |     ~ end (in_pattern.const_pattern)
         |   ~ expression (in_pattern.const_pattern.const)
@@ -9041,7 +9041,7 @@ def test_pattern_matching_const_pattern
         nil,
         s(:true)),
       %q{in A[1, 2] then true},
-      %q{    ~~~~~~ expression (in_pattern.const_pattern)
+      %q{   ~~~~~~~ expression (in_pattern.const_pattern)
         |    ~ begin (in_pattern.const_pattern)
         |         ~ end (in_pattern.const_pattern)
         |   ~ expression (in_pattern.const_pattern.const)
@@ -9057,7 +9057,7 @@ def test_pattern_matching_const_pattern
         nil,
         s(:true)),
       %q{in A[x:] then true},
-      %q{    ~~~~ expression (in_pattern.const_pattern)
+      %q{   ~~~~~ expression (in_pattern.const_pattern)
         |    ~ begin (in_pattern.const_pattern)
         |       ~ end (in_pattern.const_pattern)
         |   ~ expression (in_pattern.const_pattern.const)
@@ -9072,7 +9072,7 @@ def test_pattern_matching_const_pattern
         nil,
         s(:true)),
       %q{in A[] then true},
-      %q{    ~~ expression (in_pattern.const_pattern)
+      %q{   ~~~ expression (in_pattern.const_pattern)
         |    ~ begin (in_pattern.const_pattern)
         |     ~ end (in_pattern.const_pattern)
         |    ~~ expression (in_pattern.const_pattern.array_pattern)}