diff --git a/pkg/analyzer/lib/src/dart/constant/constant_verifier.dart b/pkg/analyzer/lib/src/dart/constant/constant_verifier.dart
index 8531759..7234756 100644
--- a/pkg/analyzer/lib/src/dart/constant/constant_verifier.dart
+++ b/pkg/analyzer/lib/src/dart/constant/constant_verifier.dart
@@ -144,6 +144,8 @@
   void visitListLiteral(ListLiteral node) {
     super.visitListLiteral(node);
     if (node.isConst) {
+      InterfaceType nodeType = node.staticType;
+      DartType elementType = nodeType.typeArguments[0];
       // Dummy sets of keys to accommodate the fact that
       // `_validateCollectionElement` handles map literals.
       HashSet<DartObject> keys = new HashSet<DartObject>();
@@ -151,7 +153,7 @@
       for (CollectionElement element in node.elements2) {
         bool isValid = _validateCollectionElement(element, true, keys,
             invalidKeys, CompileTimeErrorCode.NON_CONSTANT_LIST_ELEMENT,
-            forList: true);
+            forList: true, listElementType: elementType);
         if (isValid && element is Expression) {
           // TODO(brianwilkerson) Handle the other kinds of elements.
           _reportErrorIfFromDeferredLibrary(
@@ -176,41 +178,20 @@
     HashSet<DartObject> keys = new HashSet<DartObject>();
     List<Expression> invalidKeys = new List<Expression>();
     if (node.isSet) {
-      HashSet<DartObject> elements = new HashSet<DartObject>();
-      List<Expression> invalidElements = new List<Expression>();
       if (isConst) {
+        InterfaceType nodeType = node.staticType;
+        var elementType = nodeType.typeArguments[0];
+        var uniqueValues = Set<DartObject>();
+        var duplicateElements = <Expression>[];
         for (CollectionElement element in node.elements2) {
-          if (element is Expression) {
-            // TODO(mfairhurst): unify this with _validateCollectionElemet
-            DartObject result = _validate(
-                element, CompileTimeErrorCode.NON_CONSTANT_SET_ELEMENT);
-            if (result != null) {
-              _reportErrorIfFromDeferredLibrary(
-                  element,
-                  CompileTimeErrorCode
-                      .NON_CONSTANT_SET_ELEMENT_FROM_DEFERRED_LIBRARY);
-              if (!elements.add(result)) {
-                invalidElements.add(element);
-              }
-              DartType type = result.type;
-              if (_implementsEqualsWhenNotAllowed(type)) {
-                _errorReporter.reportErrorForNode(
-                    CompileTimeErrorCode
-                        .CONST_SET_ELEMENT_TYPE_IMPLEMENTS_EQUALS,
-                    element,
-                    [type.displayName]);
-              }
-            }
-          } else {
-            bool isValid = _validateCollectionElement(element, isConst, keys,
-                invalidKeys, CompileTimeErrorCode.NON_CONSTANT_SET_ELEMENT,
-                forSet: true);
-            if (isValid) {
-              // TODO(mfairhurst) report deferred library error
-            }
-          }
+          _validateCollectionElement(element, isConst, keys, invalidKeys,
+              CompileTimeErrorCode.NON_CONSTANT_SET_ELEMENT,
+              forSet: true,
+              setElementType: elementType,
+              setElements: uniqueValues,
+              setElementsDuplicate: duplicateElements);
         }
-        for (var invalidElement in invalidElements) {
+        for (var invalidElement in duplicateElements) {
           _errorReporter.reportErrorForNode(
               StaticWarningCode.EQUAL_VALUES_IN_CONST_SET, invalidElement);
         }
@@ -462,12 +443,62 @@
     HashSet<DartObject> keys,
     List<Expression> invalidKeys,
     ErrorCode errorCode, {
+    DartType listElementType,
+    DartType mapKeyType,
+    DartType mapValueType,
+    DartType setElementType,
+    Set<DartObject> setElements,
+    List<CollectionElement> setElementsDuplicate,
     bool forList = false,
     bool forMap = false,
     bool forSet = false,
   }) {
     if (element is Expression) {
-      return !isConst || _validate(element, errorCode) != null;
+      if (!isConst) return true;
+
+      var value = _validate(element, errorCode);
+      if (value == null) return false;
+
+      if (forList) {
+        if (!_evaluationEngine.runtimeTypeMatch(value, listElementType)) {
+          _errorReporter.reportErrorForNode(
+            StaticWarningCode.LIST_ELEMENT_TYPE_NOT_ASSIGNABLE,
+            element,
+            [value.type, listElementType],
+          );
+          return false;
+        }
+      }
+
+      if (forSet) {
+        if (!_evaluationEngine.runtimeTypeMatch(value, setElementType)) {
+          _errorReporter.reportErrorForNode(
+            StaticWarningCode.SET_ELEMENT_TYPE_NOT_ASSIGNABLE,
+            element,
+            [value.type, setElementType],
+          );
+          return false;
+        }
+
+        if (_implementsEqualsWhenNotAllowed(value.type)) {
+          _errorReporter.reportErrorForNode(
+              CompileTimeErrorCode.CONST_SET_ELEMENT_TYPE_IMPLEMENTS_EQUALS,
+              element,
+              [value.type.displayName]);
+          return false;
+        }
+
+        _reportErrorIfFromDeferredLibrary(
+          element,
+          CompileTimeErrorCode.NON_CONSTANT_SET_ELEMENT_FROM_DEFERRED_LIBRARY,
+        );
+
+        if (!setElements.add(value)) {
+          setElementsDuplicate.add(element);
+        }
+      }
+
+      return true;
     } else if (element is ForElement) {
       if (isConst) {
         _errorReporter.reportErrorForNode(errorCode, element);
@@ -483,11 +514,39 @@
           return false;
         } else if (conditionValue) {
           return _validateCollectionElement(
-                  element.thenElement, isConst, keys, invalidKeys, errorCode) !=
+                element.thenElement,
+                isConst,
+                keys,
+                invalidKeys,
+                errorCode,
+                forList: forList,
+                forMap: forMap,
+                forSet: forSet,
+                listElementType: listElementType,
+                mapKeyType: mapKeyType,
+                mapValueType: mapValueType,
+                setElementType: setElementType,
+                setElements: setElements,
+                setElementsDuplicate: setElementsDuplicate,
+              ) !=
               null;
         } else if (element.elseElement != null) {
           return _validateCollectionElement(
-                  element.elseElement, isConst, keys, invalidKeys, errorCode) !=
+                element.elseElement,
+                isConst,
+                keys,
+                invalidKeys,
+                errorCode,
+                forList: forList,
+                forMap: forMap,
+                forSet: forSet,
+                listElementType: listElementType,
+                mapKeyType: mapKeyType,
+                mapValueType: mapValueType,
+                setElementType: setElementType,
+                setElements: setElements,
+                setElementsDuplicate: setElementsDuplicate,
+              ) !=
               null;
         } else {
           return true;
diff --git a/pkg/analyzer/lib/src/generated/error_verifier.dart b/pkg/analyzer/lib/src/generated/error_verifier.dart
index 8dc85c4..8bd952c 100644
--- a/pkg/analyzer/lib/src/generated/error_verifier.dart
+++ b/pkg/analyzer/lib/src/generated/error_verifier.dart
@@ -3934,6 +3934,9 @@
    * [StaticWarningCode.LIST_ELEMENT_TYPE_NOT_ASSIGNABLE].
    */
   void _checkForListElementTypeNotAssignable(ListLiteral literal) {
+    // Constants are verified using their actual values.
+    if (literal.isConst) return;
+
     // Determine the list's element type. We base this on the static type and
     // not the literal's type arguments because in strong mode, the type
     // arguments may be inferred.
@@ -5229,6 +5232,9 @@
    * [StaticWarningCode.SET_ELEMENT_TYPE_NOT_ASSIGNABLE].
    */
   void _checkForSetElementTypeNotAssignable3(SetOrMapLiteral literal) {
+    // Constants are verified using their actual values.
+    if (literal.isConst) return;
+
     // Determine the set's element type. We base this on the static type and
     // not the literal's type arguments because in strong mode, the type
     // arguments may be inferred.
diff --git a/pkg/analyzer/test/src/diagnostics/invalid_cast_new_expr_test.dart b/pkg/analyzer/test/src/diagnostics/invalid_cast_new_expr_test.dart
index f1c94b4..7ea31a2 100644
--- a/pkg/analyzer/test/src/diagnostics/invalid_cast_new_expr_test.dart
+++ b/pkg/analyzer/test/src/diagnostics/invalid_cast_new_expr_test.dart
@@ -29,7 +29,10 @@
 class B extends A {
   const B();
 }
-''', [StrongModeCode.INVALID_CAST_NEW_EXPR]);
+''', [
+      StaticWarningCode.LIST_ELEMENT_TYPE_NOT_ASSIGNABLE,
+      StrongModeCode.INVALID_CAST_NEW_EXPR,
+    ]);
   }
 
   test_listLiteral_nonConst() async {
@@ -53,7 +56,10 @@
 class B extends A {
   const B();
 }
-''', [StrongModeCode.INVALID_CAST_NEW_EXPR]);
+''', [
+      StaticWarningCode.SET_ELEMENT_TYPE_NOT_ASSIGNABLE,
+      StrongModeCode.INVALID_CAST_NEW_EXPR,
+    ]);
   }
 
   test_setLiteral_nonConst() async {
diff --git a/pkg/analyzer/test/src/diagnostics/list_element_type_not_assignable_test.dart b/pkg/analyzer/test/src/diagnostics/list_element_type_not_assignable_test.dart
index 148844c..4d3cc5f 100644
--- a/pkg/analyzer/test/src/diagnostics/list_element_type_not_assignable_test.dart
+++ b/pkg/analyzer/test/src/diagnostics/list_element_type_not_assignable_test.dart
@@ -30,12 +30,11 @@
 ''');
   }
 
-  @FailingTest(issue: 'https://github.com/dart-lang/sdk/issues/21119')
   test_explicitTypeArgs_const_actualTypeMismatch() async {
     await assertErrorsInCode('''
 const dynamic x = 42;
 var v = const <String>[x];
-''', [CheckedModeCompileTimeErrorCode.LIST_ELEMENT_TYPE_NOT_ASSIGNABLE]);
+''', [StaticWarningCode.LIST_ELEMENT_TYPE_NOT_ASSIGNABLE]);
   }
 
   test_explicitTypeArgs_notConst() async {
@@ -52,15 +51,82 @@
   AnalysisOptionsImpl get analysisOptions => AnalysisOptionsImpl()
     ..enabledExperiments = ['control-flow-collections', 'spread-collections'];
 
-  test_spread_valid_const() async {
+  test_const_ifElement_thenElseFalse_intInt() async {
     await assertNoErrorsInCode('''
-var v = const <String>[...['a', 'b']];
+const dynamic a = 0;
+const dynamic b = 0;
+var v = <int>[if (1 < 0) a else b];
 ''');
   }
 
-  test_spread_valid_nonConst() async {
+  test_const_ifElement_thenElseFalse_intString() async {
+    await assertErrorsInCode('''
+const dynamic a = 0;
+const dynamic b = 'b';
+var v = const <int>[if (1 < 0) a else b];
+''', [StaticWarningCode.LIST_ELEMENT_TYPE_NOT_ASSIGNABLE]);
+  }
+
+  test_const_ifElement_thenFalse_intString() async {
     await assertNoErrorsInCode('''
-var v = <String>[...['a', 'b']];
+const dynamic a = 'a';
+var v = const <int>[if (1 < 0) a];
+''');
+  }
+
+  test_const_ifElement_thenTrue_intInt() async {
+    await assertNoErrorsInCode('''
+const dynamic a = 0;
+var v = <int>[if (true) a];
+''');
+  }
+
+  test_const_ifElement_thenTrue_intString() async {
+    await assertErrorsInCode('''
+const dynamic a = 'a';
+var v = const <int>[if (true) a];
+''', [StaticWarningCode.LIST_ELEMENT_TYPE_NOT_ASSIGNABLE]);
+  }
+
+  test_const_spread_intInt() async {
+    await assertNoErrorsInCode('''
+var v = const <int>[...[0, 1]];
+''');
+  }
+
+  test_nonConst_ifElement_thenElseFalse_intDynamic() async {
+    await assertNoErrorsInCode('''
+const dynamic a = 'a';
+const dynamic b = 'b';
+var v = <int>[if (1 < 0) a else b];
+''');
+  }
+
+  test_nonConst_ifElement_thenElseFalse_intInt() async {
+    await assertNoErrorsInCode('''
+const dynamic a = 0;
+const dynamic b = 0;
+var v = <int>[if (1 < 0) a else b];
+''');
+  }
+
+  test_nonConst_ifElement_thenTrue_intDynamic() async {
+    await assertNoErrorsInCode('''
+const dynamic a = 'a';
+var v = <int>[if (true) a];
+''');
+  }
+
+  test_nonConst_ifElement_thenTrue_intInt() async {
+    await assertNoErrorsInCode('''
+const dynamic a = 0;
+var v = <int>[if (true) a];
+''');
+  }
+
+  test_nonConst_spread_intInt() async {
+    await assertNoErrorsInCode('''
+var v = <int>[...[0, 1]];
 ''');
   }
 }
diff --git a/pkg/analyzer/test/src/diagnostics/set_element_type_not_assignable_test.dart b/pkg/analyzer/test/src/diagnostics/set_element_type_not_assignable_test.dart
index 61ebabe..54f9514 100644
--- a/pkg/analyzer/test/src/diagnostics/set_element_type_not_assignable_test.dart
+++ b/pkg/analyzer/test/src/diagnostics/set_element_type_not_assignable_test.dart
@@ -52,15 +52,82 @@
   AnalysisOptionsImpl get analysisOptions => AnalysisOptionsImpl()
     ..enabledExperiments = ['control-flow-collections', 'spread-collections'];
 
-  test_spread_valid_const() async {
+  test_const_ifElement_thenElseFalse_intInt() async {
     await assertNoErrorsInCode('''
-var v = const <String>{...['a', 'b']};
+const dynamic a = 0;
+const dynamic b = 0;
+var v = <int>{if (1 < 0) a else b};
 ''');
   }
 
-  test_spread_valid_nonConst() async {
+  test_const_ifElement_thenElseFalse_intString() async {
+    await assertErrorsInCode('''
+const dynamic a = 0;
+const dynamic b = 'b';
+var v = const <int>{if (1 < 0) a else b};
+''', [StaticWarningCode.SET_ELEMENT_TYPE_NOT_ASSIGNABLE]);
+  }
+
+  test_const_ifElement_thenFalse_intString() async {
     await assertNoErrorsInCode('''
-var v = <String>{...['a', 'b']};
+const dynamic a = 'a';
+var v = const <int>{if (1 < 0) a};
+''');
+  }
+
+  test_const_ifElement_thenTrue_intInt() async {
+    await assertNoErrorsInCode('''
+const dynamic a = 0;
+var v = <int>{if (true) a};
+''');
+  }
+
+  test_const_ifElement_thenTrue_intString() async {
+    await assertErrorsInCode('''
+const dynamic a = 'a';
+var v = const <int>{if (true) a};
+''', [StaticWarningCode.SET_ELEMENT_TYPE_NOT_ASSIGNABLE]);
+  }
+
+  test_const_spread_intInt() async {
+    await assertNoErrorsInCode('''
+var v = const <int>{...[0, 1]};
+''');
+  }
+
+  test_nonConst_ifElement_thenElseFalse_intDynamic() async {
+    await assertNoErrorsInCode('''
+const dynamic a = 'a';
+const dynamic b = 'b';
+var v = <int>{if (1 < 0) a else b};
+''');
+  }
+
+  test_nonConst_ifElement_thenElseFalse_intInt() async {
+    await assertNoErrorsInCode('''
+const dynamic a = 0;
+const dynamic b = 0;
+var v = <int>{if (1 < 0) a else b};
+''');
+  }
+
+  test_nonConst_ifElement_thenTrue_intDynamic() async {
+    await assertNoErrorsInCode('''
+const dynamic a = 'a';
+var v = <int>{if (true) a};
+''');
+  }
+
+  test_nonConst_ifElement_thenTrue_intInt() async {
+    await assertNoErrorsInCode('''
+const dynamic a = 0;
+var v = <int>{if (true) a};
+''');
+  }
+
+  test_nonConst_spread_intInt() async {
+    await assertNoErrorsInCode('''
+var v = <int>{...[0, 1]};
 ''');
   }
 }