diff --git a/src/sqlfluff/dialects/dialect_duckdb.py b/src/sqlfluff/dialects/dialect_duckdb.py
index 4b41b37b118..51e71a996fc 100644
--- a/src/sqlfluff/dialects/dialect_duckdb.py
+++ b/src/sqlfluff/dialects/dialect_duckdb.py
@@ -10,6 +10,7 @@
     BinaryOperatorSegment,
     Bracketed,
     CodeSegment,
+    ComparisonOperatorSegment,
     Dedent,
     Delimited,
     IdentifierSegment,
@@ -74,6 +75,7 @@
 duckdb_dialect.add(
     LambdaArrowSegment=StringParser("->", SymbolSegment, type="lambda_arrow"),
     OrIgnoreGrammar=Sequence("OR", "IGNORE"),
+    EqualsSegment_a=StringParser("==", ComparisonOperatorSegment),
 )
 
 duckdb_dialect.replace(
@@ -142,6 +144,13 @@
         "single_quote", IdentifierSegment, type="quoted_identifier", casefold=str.lower
     ),
     ListComprehensionGrammar=Ref("ListComprehensionExpressionSegment"),
+    ComparisonOperatorGrammar=ansi_dialect.get_grammar(
+        "ComparisonOperatorGrammar"
+    ).copy(
+        insert=[
+            Ref("EqualsSegment_a"),
+        ]
+    ),
 )
 
 duckdb_dialect.insert_lexer_matchers(
@@ -173,6 +182,7 @@
                 "escape_replacements": [(r'""', '"')],
             },
         ),
+        RegexLexer("equals", r"==?", CodeSegment),
     ]
 )
 
diff --git a/test/fixtures/dialects/duckdb/double_equal.sql b/test/fixtures/dialects/duckdb/double_equal.sql
new file mode 100644
index 00000000000..427afdd1590
--- /dev/null
+++ b/test/fixtures/dialects/duckdb/double_equal.sql
@@ -0,0 +1,7 @@
+SELECT
+    COALESCE(
+        MAX(CASE WHEN col1 == 'A' THEN cola END),
+        MAX(CASE WHEN col1 == 'B' THEN colb END),
+        MAX(CASE WHEN col1 = 'C' THEN colb END)
+    ) AS result
+FROM my_table;
diff --git a/test/fixtures/dialects/duckdb/double_equal.yml b/test/fixtures/dialects/duckdb/double_equal.yml
new file mode 100644
index 00000000000..0117b453457
--- /dev/null
+++ b/test/fixtures/dialects/duckdb/double_equal.yml
@@ -0,0 +1,102 @@
+# YML test files are auto-generated from SQL files and should not be edited by
+# hand. To help enforce this, the "hash" field in the file must match a hash
+# computed by SQLFluff when running the tests. Please run
+# `python test/generate_parse_fixture_yml.py`  to generate them after adding or
+# altering SQL files.
+_hash: 8f84857317f2db485136f25707f1a315933c79426a5b55ed8d253d5370903bfd
+file:
+  statement:
+    select_statement:
+      select_clause:
+        keyword: SELECT
+        select_clause_element:
+          function:
+            function_name:
+              function_name_identifier: COALESCE
+            function_contents:
+              bracketed:
+              - start_bracket: (
+              - expression:
+                  function:
+                    function_name:
+                      function_name_identifier: MAX
+                    function_contents:
+                      bracketed:
+                        start_bracket: (
+                        expression:
+                          case_expression:
+                          - keyword: CASE
+                          - when_clause:
+                            - keyword: WHEN
+                            - expression:
+                                column_reference:
+                                  naked_identifier: col1
+                                comparison_operator: ==
+                                quoted_literal: "'A'"
+                            - keyword: THEN
+                            - expression:
+                                column_reference:
+                                  naked_identifier: cola
+                          - keyword: END
+                        end_bracket: )
+              - comma: ','
+              - expression:
+                  function:
+                    function_name:
+                      function_name_identifier: MAX
+                    function_contents:
+                      bracketed:
+                        start_bracket: (
+                        expression:
+                          case_expression:
+                          - keyword: CASE
+                          - when_clause:
+                            - keyword: WHEN
+                            - expression:
+                                column_reference:
+                                  naked_identifier: col1
+                                comparison_operator: ==
+                                quoted_literal: "'B'"
+                            - keyword: THEN
+                            - expression:
+                                column_reference:
+                                  naked_identifier: colb
+                          - keyword: END
+                        end_bracket: )
+              - comma: ','
+              - expression:
+                  function:
+                    function_name:
+                      function_name_identifier: MAX
+                    function_contents:
+                      bracketed:
+                        start_bracket: (
+                        expression:
+                          case_expression:
+                          - keyword: CASE
+                          - when_clause:
+                            - keyword: WHEN
+                            - expression:
+                                column_reference:
+                                  naked_identifier: col1
+                                comparison_operator:
+                                  raw_comparison_operator: '='
+                                quoted_literal: "'C'"
+                            - keyword: THEN
+                            - expression:
+                                column_reference:
+                                  naked_identifier: colb
+                          - keyword: END
+                        end_bracket: )
+              - end_bracket: )
+          alias_expression:
+            keyword: AS
+            naked_identifier: result
+      from_clause:
+        keyword: FROM
+        from_expression:
+          from_expression_element:
+            table_expression:
+              table_reference:
+                naked_identifier: my_table
+  statement_terminator: ;