diff --git a/pkg/front_end/lib/src/fasta/fasta_codes_generated.dart b/pkg/front_end/lib/src/fasta/fasta_codes_generated.dart
index 0cb1431..bdee95c 100644
--- a/pkg/front_end/lib/src/fasta/fasta_codes_generated.dart
+++ b/pkg/front_end/lib/src/fasta/fasta_codes_generated.dart
@@ -5931,7 +5931,7 @@
     "MapLiteralTypeArgumentMismatch",
     analyzerCodes: <String>["EXPECTED_TWO_MAP_TYPE_ARGUMENTS"],
     severity: Severity.errorLegacyWarning,
-    message: r"""Map literal requires exactly two type arguments.""");
+    message: r"""A map literal requires exactly two type arguments.""");
 
 // DO NOT EDIT. THIS FILE IS GENERATED. SEE TOP OF FILE.
 const Code<Null> codeMemberWithSameNameAsClass =
@@ -7861,7 +7861,18 @@
 const MessageCode messageSetLiteralTooManyTypeArguments = const MessageCode(
     "SetLiteralTooManyTypeArguments",
     severity: Severity.errorLegacyWarning,
-    message: r"""Set literal requires exactly one type argument.""");
+    message: r"""A set literal requires exactly one type argument.""");
+
+// DO NOT EDIT. THIS FILE IS GENERATED. SEE TOP OF FILE.
+const Code<Null> codeSetOrMapLiteralTooManyTypeArguments =
+    messageSetOrMapLiteralTooManyTypeArguments;
+
+// DO NOT EDIT. THIS FILE IS GENERATED. SEE TOP OF FILE.
+const MessageCode messageSetOrMapLiteralTooManyTypeArguments = const MessageCode(
+    "SetOrMapLiteralTooManyTypeArguments",
+    severity: Severity.errorLegacyWarning,
+    message:
+        r"""A set or map literal requires exactly one or two type arguments, respectively.""");
 
 // DO NOT EDIT. THIS FILE IS GENERATED. SEE TOP OF FILE.
 const Template<Message Function(String name)> templateSetterNotFound =
diff --git a/pkg/front_end/lib/src/fasta/kernel/body_builder.dart b/pkg/front_end/lib/src/fasta/kernel/body_builder.dart
index 5d3ad9e..a6659ff 100644
--- a/pkg/front_end/lib/src/fasta/kernel/body_builder.dart
+++ b/pkg/front_end/lib/src/fasta/kernel/body_builder.dart
@@ -2345,7 +2345,13 @@
     debugEvent("EmptyLiteralSetOrMap");
     // Treat as map literal - type inference will find the right type.
     List<UnresolvedType<KernelTypeBuilder>> typeArguments = pop();
-    assert(typeArguments == null);
+    assert(typeArguments == null || typeArguments.length > 2);
+    if (typeArguments != null && typeArguments.length > 2) {
+      addProblem(
+          fasta.messageSetOrMapLiteralTooManyTypeArguments,
+          offsetForToken(leftBrace),
+          lengthOfSpan(leftBrace, leftBrace.endGroup));
+    }
     push(forest.literalMap(
         constKeyword,
         constKeyword != null || constantContext == ConstantContext.inferred,
diff --git a/pkg/front_end/lib/src/fasta/parser/parser.dart b/pkg/front_end/lib/src/fasta/parser/parser.dart
index 9e1f015..8b0ff26 100644
--- a/pkg/front_end/lib/src/fasta/parser/parser.dart
+++ b/pkg/front_end/lib/src/fasta/parser/parser.dart
@@ -4451,8 +4451,6 @@
         case 2:
           return parseLiteralMapSuffix(token, constKeyword);
         default:
-          // TODO(danrubel): Add a compile time warning that set literals
-          // require one type argument and map literals require two.
           return parseLiteralSetOrMapSuffix(token, constKeyword);
       }
     }
diff --git a/pkg/front_end/messages.status b/pkg/front_end/messages.status
index c444a6d..8001c80 100644
--- a/pkg/front_end/messages.status
+++ b/pkg/front_end/messages.status
@@ -313,6 +313,8 @@
 SdkSummaryNotFound/example: Fail
 SetLiteralTooManyTypeArguments/analyzerCode: Fail
 SetLiteralTooManyTypeArguments/example: Fail
+SetOrMapLiteralTooManyTypeArguments/analyzerCode: Fail
+SetOrMapLiteralTooManyTypeArguments/example: Fail
 SetterNotFound/example: Fail
 SetterNotSync/example: Fail
 SetterWithWrongNumberOfFormals/example: Fail
diff --git a/pkg/front_end/messages.yaml b/pkg/front_end/messages.yaml
index 86aad34..5f6e9b5 100644
--- a/pkg/front_end/messages.yaml
+++ b/pkg/front_end/messages.yaml
@@ -1440,14 +1440,18 @@
   analyzerCode: EXPECTED_ONE_LIST_TYPE_ARGUMENTS
 
 SetLiteralTooManyTypeArguments:
-  template: "Set literal requires exactly one type argument."
+  template: "A set literal requires exactly one type argument."
   severity: ERROR_LEGACY_WARNING
 
 MapLiteralTypeArgumentMismatch:
-  template: "Map literal requires exactly two type arguments."
+  template: "A map literal requires exactly two type arguments."
   severity: ERROR_LEGACY_WARNING
   analyzerCode: EXPECTED_TWO_MAP_TYPE_ARGUMENTS
 
+SetOrMapLiteralTooManyTypeArguments:
+  template: "A set or map literal requires exactly one or two type arguments, respectively."
+  severity: ERROR_LEGACY_WARNING
+
 LoadLibraryTakesNoArguments:
   template: "'loadLibrary' takes no arguments."
   severity: ERROR_LEGACY_WARNING