diff --git a/lib/processor.js b/lib/processor.js
index 91aeacfc9..8a463c7fb 100644
--- a/lib/processor.js
+++ b/lib/processor.js
@@ -94,11 +94,6 @@ class Processor {
         return displayGrid || gridTemplate || gridGap
       })
     }
-    function insideFlex(decl) {
-      return decl.parent.some(node => {
-        return node.prop === 'display' && /(inline-)?flex/.test(node.value)
-      })
-    }
 
     let gridPrefixes =
       this.gridStatus(css, result) &&
@@ -147,17 +142,6 @@ class Processor {
             { node: decl }
           )
         }
-      } else if (
-        /^(align|justify|place)-(items|content)$/.test(prop) &&
-        insideFlex(decl)
-      ) {
-        if (value === 'start' || value === 'end') {
-          result.warn(
-            `${value} value has mixed support, consider using ` +
-              `flex-${value} instead`,
-            { node: decl }
-          )
-        }
       } else if (prop === 'text-decoration-skip' && value === 'ink') {
         result.warn(
           'Replace text-decoration-skip: ink to ' +
diff --git a/test/autoprefixer.test.js b/test/autoprefixer.test.js
index b94deae99..0c5eff646 100644
--- a/test/autoprefixer.test.js
+++ b/test/autoprefixer.test.js
@@ -903,25 +903,6 @@ test('warns on old flexbox display', () => {
   )
 })
 
-test('warns on mixed support usage', () => {
-  let css = 'a { display: flex; align-content: start; justify-content: end; }'
-  let result = postcss([
-    autoprefixer({
-      overrideBrowserslist: ['IE 11']
-    })
-  ]).process(css)
-  equal(result.css, css)
-  equal(
-    result.warnings().map(i => i.toString()),
-    [
-      'autoprefixer: <css input>:1:20: start value has mixed support, ' +
-        'consider using flex-start instead',
-      'autoprefixer: <css input>:1:42: end value has mixed support, ' +
-        'consider using flex-end instead'
-    ]
-  )
-})
-
 test('supports intrinsic sizing', () => {
   let input = read('intrinsic')
   let output = read('intrinsic.out')