diff --git a/lib/rules/declaration-block-no-duplicate-properties/README.md b/lib/rules/declaration-block-no-duplicate-properties/README.md
index a8bd6b7980..258f9d5cdd 100644
--- a/lib/rules/declaration-block-no-duplicate-properties/README.md
+++ b/lib/rules/declaration-block-no-duplicate-properties/README.md
@@ -11,6 +11,8 @@ a { color: pink; color: orange; }
 
 This rule ignores variables (`$sass`, `@less`, `--custom-property`).
 
+The [`fix` option](../../../docs/user-guide/usage/options.md#fix) can automatically fix all of the problems reported by this rule.
+
 ## Options
 
 ### `true`
diff --git a/lib/rules/declaration-block-no-duplicate-properties/index.js b/lib/rules/declaration-block-no-duplicate-properties/index.js
index 30784f3aac..81253bf7bf 100644
--- a/lib/rules/declaration-block-no-duplicate-properties/index.js
+++ b/lib/rules/declaration-block-no-duplicate-properties/index.js
@@ -18,6 +18,7 @@ const messages = ruleMessages(ruleName, {
 
 const meta = {
 	url: 'https://stylelint.io/user-guide/rules/list/declaration-block-no-duplicate-properties',
+	fixable: true,
 };
 
 /** @type {import('stylelint').Rule} */
@@ -60,13 +61,10 @@ const rule = (primary, secondaryOptions, context) => {
 		eachDeclarationBlock(root, (eachDecl) => {
 			/** @type {import('postcss').Declaration[]} */
 			const decls = [];
-			/** @type {string[]} */
-			const declsProps = [];
-			/** @type {string[]} */
-			const values = [];
 
 			eachDecl((decl) => {
 				const prop = decl.prop;
+				const lowerProp = decl.prop.toLowerCase();
 				const value = decl.value;
 
 				if (!isStandardSyntaxProperty(prop)) {
@@ -83,18 +81,18 @@ const rule = (primary, secondaryOptions, context) => {
 				}
 
 				// Ignore the src property as commonly duplicated in at-fontface
-				if (prop.toLowerCase() === 'src') {
+				if (lowerProp === 'src') {
 					return;
 				}
 
-				const indexDuplicate = declsProps.indexOf(prop.toLowerCase());
+				const indexDuplicate = decls.findIndex((d) => d.prop.toLowerCase() === lowerProp);
 
 				if (indexDuplicate !== -1) {
 					if (ignoreDiffValues || ignorePrefixlessSameValues) {
 						// fails if duplicates are not consecutive
-						if (indexDuplicate !== declsProps.length - 1) {
+						if (indexDuplicate !== decls.length - 1) {
 							if (context.fix) {
-								removePreviousDuplicate(decls, prop);
+								removePreviousDuplicate(decls, lowerProp);
 
 								return;
 							}
@@ -110,13 +108,14 @@ const rule = (primary, secondaryOptions, context) => {
 							return;
 						}
 
-						const duplicateValue = values[indexDuplicate] || '';
+						const duplicateDecl = decls[indexDuplicate];
+						const duplicateValue = duplicateDecl ? duplicateDecl.value : '';
 
 						if (ignorePrefixlessSameValues) {
 							// fails if values of consecutive, unprefixed duplicates are equal
 							if (vendor.unprefixed(value) !== vendor.unprefixed(duplicateValue)) {
 								if (context.fix) {
-									removePreviousDuplicate(decls, prop);
+									removePreviousDuplicate(decls, lowerProp);
 
 									return;
 								}
@@ -136,7 +135,7 @@ const rule = (primary, secondaryOptions, context) => {
 						// fails if values of consecutive duplicates are equal
 						if (value === duplicateValue) {
 							if (context.fix) {
-								removePreviousDuplicate(decls, prop);
+								removePreviousDuplicate(decls, lowerProp);
 
 								return;
 							}
@@ -155,12 +154,12 @@ const rule = (primary, secondaryOptions, context) => {
 						return;
 					}
 
-					if (ignoreDuplicates && indexDuplicate === declsProps.length - 1) {
+					if (ignoreDuplicates && indexDuplicate === decls.length - 1) {
 						return;
 					}
 
 					if (context.fix) {
-						removePreviousDuplicate(decls, prop);
+						removePreviousDuplicate(decls, lowerProp);
 
 						return;
 					}
@@ -175,8 +174,6 @@ const rule = (primary, secondaryOptions, context) => {
 				}
 
 				decls.push(decl);
-				declsProps.push(prop.toLowerCase());
-				values.push(value.toLowerCase());
 			});
 		});
 	};
@@ -184,11 +181,11 @@ const rule = (primary, secondaryOptions, context) => {
 
 /**
  * @param {import('postcss').Declaration[]} declarations
- * @param {string} property
+ * @param {string} lowerProperty
  * @returns {void}
  * */
-function removePreviousDuplicate(declarations, property) {
-	const declToRemove = declarations.find((d) => d.prop.toLowerCase() === property.toLowerCase());
+function removePreviousDuplicate(declarations, lowerProperty) {
+	const declToRemove = declarations.find((d) => d.prop.toLowerCase() === lowerProperty);
 
 	if (declToRemove) declToRemove.remove();
 }