diff --git a/src/lexer/sql/test.rs b/src/lexer/sql/test.rs
index 54fb927..28d0228 100644
--- a/src/lexer/sql/test.rs
+++ b/src/lexer/sql/test.rs
@@ -48,6 +48,14 @@ fn duplicate_column() {
         b"CREATE TABLE t (x TEXT, x TEXT)",
         "duplicate column name: x",
     );
+    expect_parser_err_msg(
+        b"CREATE TABLE t (x TEXT, \"x\" TEXT)",
+        "duplicate column name: x",
+    );
+    expect_parser_err_msg(
+        b"CREATE TABLE t (x TEXT, `x` TEXT)",
+        "duplicate column name: x",
+    );
 }
 
 #[test]
diff --git a/src/parser/ast/fmt.rs b/src/parser/ast/fmt.rs
index 7919313..a548b64 100644
--- a/src/parser/ast/fmt.rs
+++ b/src/parser/ast/fmt.rs
@@ -2035,3 +2035,57 @@ fn double_quote<S: TokenStream>(name: &str, s: &mut S) -> Result<(), S::Error> {
     f.write_char('"')*/
     s.append(TK_ID, Some(name))
 }
+
+/// Convert an SQL-style quoted string into a normal string by removing
+/// the quote characters.
+pub fn dequote(n: Name) -> Result<Name, ParserError> {
+    let s = n.0.as_str();
+    if s.is_empty() {
+        return Ok(n);
+    }
+    let mut quote = s.chars().nth(0).unwrap();
+    if quote != '"' && quote != '`' && quote != '\'' && quote != '[' {
+        return Ok(n);
+    } else if quote == '[' {
+        quote = ']';
+    }
+    debug_assert!(s.len() > 1);
+    debug_assert!(s.ends_with(quote));
+    let sub = &s[1..s.len() - 1];
+    let mut z = String::with_capacity(sub.len());
+    let mut escaped = false;
+    for c in sub.chars() {
+        if escaped {
+            if c != quote {
+                return Err(custom_err!("Malformed string literal: {}", s));
+            }
+            escaped = false;
+        } else if c == quote {
+            escaped = true;
+            continue;
+        }
+        z.push(c);
+    }
+    Ok(Name(Uncased::from_owned(z)))
+}
+
+#[cfg(test)]
+mod test {
+    use super::{dequote, Name, ParserError};
+    use uncased::Uncased;
+
+    #[test]
+    fn test_dequote() -> Result<(), ParserError> {
+        assert_eq!(dequote(name("x"))?, name("x"));
+        assert_eq!(dequote(name("`x`"))?, name("x"));
+        assert_eq!(dequote(name("`x``y`"))?, name("x`y"));
+        assert_eq!(dequote(name(r#""x""#))?, name("x"));
+        assert_eq!(dequote(name(r#""x""y""#))?, name("x\"y"));
+        assert_eq!(dequote(name("[x]"))?, name("x"));
+        Ok(())
+    }
+
+    fn name(s: &'static str) -> Name {
+        Name(Uncased::from_borrowed(s))
+    }
+}
diff --git a/src/parser/ast/mod.rs b/src/parser/ast/mod.rs
index 8f295ed..b345254 100644
--- a/src/parser/ast/mod.rs
+++ b/src/parser/ast/mod.rs
@@ -6,7 +6,7 @@ pub mod fmt;
 use std::num::ParseIntError;
 use std::str::FromStr;
 
-use fmt::{ToTokens, TokenStream};
+use fmt::{dequote, ToTokens, TokenStream};
 use indexmap::{IndexMap, IndexSet};
 use uncased::Uncased;
 
@@ -1116,9 +1116,10 @@ impl ColumnDefinition {
         columns: &mut IndexMap<Name, ColumnDefinition>,
         mut cd: ColumnDefinition,
     ) -> Result<(), ParserError> {
-        if columns.contains_key(&cd.col_name) {
+        let col_name = dequote(cd.col_name.clone())?;
+        if columns.contains_key(&col_name) {
             // TODO unquote
-            return Err(custom_err!("duplicate column name: {}", cd.col_name));
+            return Err(custom_err!("duplicate column name: {}", col_name));
         }
         // https://github.com/sqlite/sqlite/blob/e452bf40a14aca57fd9047b330dff282f3e4bbcc/src/build.c#L1511-L1514
         if let Some(ref mut col_type) = cd.col_type {
@@ -1147,7 +1148,7 @@ impl ColumnDefinition {
                 col_type.name = new_type.join(" ");
             }
         }
-        columns.insert(cd.col_name.clone(), cd);
+        columns.insert(col_name, cd);
         Ok(())
     }
 }
diff --git a/src/parser/parse.y b/src/parser/parse.y
index bbace83..4e8614e 100644
--- a/src/parser/parse.y
+++ b/src/parser/parse.y
@@ -166,8 +166,9 @@ columnlist(A) ::= columnlist(A) COMMA columnname(X) carglist(Y). {
 }
 columnlist(A) ::= columnname(X) carglist(Y). {
   let col = X;
+  let cd = ColumnDefinition{ col_name: col.0, col_type: col.1, constraints: Y };
   let mut map = IndexMap::new();
-  map.insert(col.0.clone(), ColumnDefinition{ col_name: col.0, col_type: col.1, constraints: Y });
+  ColumnDefinition::add_column(&mut map, cd)?;
   A = map;
 }
 %type columnname {(Name, Option<Type>)}