diff --git a/src/compiler/checker.ts b/src/compiler/checker.ts
index a16cab1443c..308f3a61b2c 100644
--- a/src/compiler/checker.ts
+++ b/src/compiler/checker.ts
@@ -30128,6 +30128,12 @@ namespace ts {
                 (<PrefixUnaryExpression>expr).operand.kind === SyntaxKind.NumericLiteral;
         }
 
+        function isBigIntLiteralExpression(expr: Expression) {
+            return expr.kind === SyntaxKind.BigIntLiteral ||
+                expr.kind === SyntaxKind.PrefixUnaryExpression && (<PrefixUnaryExpression>expr).operator === SyntaxKind.MinusToken &&
+                (<PrefixUnaryExpression>expr).operand.kind === SyntaxKind.BigIntLiteral;
+        }
+
         function isSimpleLiteralEnumReference(expr: Expression) {
             if (
                 (isPropertyAccessExpression(expr) || (isElementAccessExpression(expr) && isStringOrNumberLiteralExpression(expr.argumentExpression))) &&
@@ -30136,19 +30142,25 @@ namespace ts {
         }
 
         function checkAmbientInitializer(node: VariableDeclaration | PropertyDeclaration | PropertySignature) {
-            if (node.initializer) {
-                const isInvalidInitializer = !(isStringOrNumberLiteralExpression(node.initializer) || isSimpleLiteralEnumReference(node.initializer) || node.initializer.kind === SyntaxKind.TrueKeyword || node.initializer.kind === SyntaxKind.FalseKeyword);
+            const {initializer} = node;
+            if (initializer) {
+                const isInvalidInitializer = !(
+                    isStringOrNumberLiteralExpression(initializer) ||
+                    isSimpleLiteralEnumReference(initializer) ||
+                    initializer.kind === SyntaxKind.TrueKeyword || initializer.kind === SyntaxKind.FalseKeyword ||
+                    isBigIntLiteralExpression(initializer)
+                );
                 const isConstOrReadonly = isDeclarationReadonly(node) || isVariableDeclaration(node) && isVarConst(node);
                 if (isConstOrReadonly && !node.type) {
                     if (isInvalidInitializer) {
-                        return grammarErrorOnNode(node.initializer!, Diagnostics.A_const_initializer_in_an_ambient_context_must_be_a_string_or_numeric_literal_or_literal_enum_reference);
+                        return grammarErrorOnNode(initializer, Diagnostics.A_const_initializer_in_an_ambient_context_must_be_a_string_or_numeric_literal_or_literal_enum_reference);
                     }
                 }
                 else {
-                    return grammarErrorOnNode(node.initializer!, Diagnostics.Initializers_are_not_allowed_in_ambient_contexts);
+                    return grammarErrorOnNode(initializer, Diagnostics.Initializers_are_not_allowed_in_ambient_contexts);
                 }
                 if (!isConstOrReadonly || isInvalidInitializer) {
-                    return grammarErrorOnNode(node.initializer!, Diagnostics.Initializers_are_not_allowed_in_ambient_contexts);
+                    return grammarErrorOnNode(initializer, Diagnostics.Initializers_are_not_allowed_in_ambient_contexts);
                 }
             }
         }
diff --git a/tests/baselines/reference/bigintWithLib.errors.txt b/tests/baselines/reference/bigintWithLib.errors.txt
index a24f6ac4802..18267e6ffdf 100644
--- a/tests/baselines/reference/bigintWithLib.errors.txt
+++ b/tests/baselines/reference/bigintWithLib.errors.txt
@@ -74,4 +74,10 @@ tests/cases/compiler/bigintWithLib.ts(43,26): error TS2345: Argument of type '12
     bigintVal = dataView.getBigInt64(1);
     bigintVal = dataView.getBigInt64(1, true);
     bigintVal = dataView.getBigUint64(2);
-    bigintVal = dataView.getBigUint64(2, true);
\ No newline at end of file
+    bigintVal = dataView.getBigUint64(2, true);
+    
+    // Test emitted declarations files
+    const w = 12n; // should emit as const w = 12n
+    const x = -12n; // should emit as const x = -12n
+    const y: 12n = 12n; // should emit type 12n
+    let z = 12n; // should emit type bigint in declaration file
\ No newline at end of file
diff --git a/tests/baselines/reference/bigintWithLib.js b/tests/baselines/reference/bigintWithLib.js
index 979e0d2b129..754b2144f0c 100644
--- a/tests/baselines/reference/bigintWithLib.js
+++ b/tests/baselines/reference/bigintWithLib.js
@@ -45,7 +45,13 @@ dataView.setBigUint64(2, 123); // should error
 bigintVal = dataView.getBigInt64(1);
 bigintVal = dataView.getBigInt64(1, true);
 bigintVal = dataView.getBigUint64(2);
-bigintVal = dataView.getBigUint64(2, true);
+bigintVal = dataView.getBigUint64(2, true);
+
+// Test emitted declarations files
+const w = 12n; // should emit as const w = 12n
+const x = -12n; // should emit as const x = -12n
+const y: 12n = 12n; // should emit type 12n
+let z = 12n; // should emit type bigint in declaration file
 
 //// [bigintWithLib.js]
 // Test BigInt functions
@@ -92,3 +98,22 @@ bigintVal = dataView.getBigInt64(1);
 bigintVal = dataView.getBigInt64(1, true);
 bigintVal = dataView.getBigUint64(2);
 bigintVal = dataView.getBigUint64(2, true);
+// Test emitted declarations files
+const w = 12n; // should emit as const w = 12n
+const x = -12n; // should emit as const x = -12n
+const y = 12n; // should emit type 12n
+let z = 12n; // should emit type bigint in declaration file
+
+
+//// [bigintWithLib.d.ts]
+declare let bigintVal: bigint;
+declare let stringVal: string;
+declare let bigIntArray: BigInt64Array;
+declare let len: number;
+declare let arrayBufferLike: ArrayBufferView;
+declare let bigUintArray: BigUint64Array;
+declare const dataView: DataView;
+declare const w = 12n;
+declare const x = -12n;
+declare const y: 12n;
+declare let z: bigint;
diff --git a/tests/baselines/reference/bigintWithLib.symbols b/tests/baselines/reference/bigintWithLib.symbols
index 0f313251ab0..cdc80161a45 100644
--- a/tests/baselines/reference/bigintWithLib.symbols
+++ b/tests/baselines/reference/bigintWithLib.symbols
@@ -204,3 +204,16 @@ bigintVal = dataView.getBigUint64(2, true);
 >dataView : Symbol(dataView, Decl(bigintWithLib.ts, 36, 5))
 >getBigUint64 : Symbol(DataView.getBigUint64, Decl(lib.esnext.bigint.d.ts, --, --))
 
+// Test emitted declarations files
+const w = 12n; // should emit as const w = 12n
+>w : Symbol(w, Decl(bigintWithLib.ts, 49, 5))
+
+const x = -12n; // should emit as const x = -12n
+>x : Symbol(x, Decl(bigintWithLib.ts, 50, 5))
+
+const y: 12n = 12n; // should emit type 12n
+>y : Symbol(y, Decl(bigintWithLib.ts, 51, 5))
+
+let z = 12n; // should emit type bigint in declaration file
+>z : Symbol(z, Decl(bigintWithLib.ts, 52, 3))
+
diff --git a/tests/baselines/reference/bigintWithLib.types b/tests/baselines/reference/bigintWithLib.types
index 5ba273091b6..a1d79119cf6 100644
--- a/tests/baselines/reference/bigintWithLib.types
+++ b/tests/baselines/reference/bigintWithLib.types
@@ -332,3 +332,21 @@ bigintVal = dataView.getBigUint64(2, true);
 >2 : 2
 >true : true
 
+// Test emitted declarations files
+const w = 12n; // should emit as const w = 12n
+>w : 12n
+>12n : 12n
+
+const x = -12n; // should emit as const x = -12n
+>x : -12n
+>-12n : -12n
+>12n : 12n
+
+const y: 12n = 12n; // should emit type 12n
+>y : 12n
+>12n : 12n
+
+let z = 12n; // should emit type bigint in declaration file
+>z : bigint
+>12n : 12n
+
diff --git a/tests/cases/compiler/bigintWithLib.ts b/tests/cases/compiler/bigintWithLib.ts
index 3299b1ecc83..0cefd3094d4 100644
--- a/tests/cases/compiler/bigintWithLib.ts
+++ b/tests/cases/compiler/bigintWithLib.ts
@@ -1,5 +1,6 @@
 // @experimentalBigInt: true
 // @target: esnext
+// @declaration: true
 
 // Test BigInt functions
 let bigintVal: bigint = BigInt(123);
@@ -47,4 +48,10 @@ dataView.setBigUint64(2, 123); // should error
 bigintVal = dataView.getBigInt64(1);
 bigintVal = dataView.getBigInt64(1, true);
 bigintVal = dataView.getBigUint64(2);
-bigintVal = dataView.getBigUint64(2, true);
\ No newline at end of file
+bigintVal = dataView.getBigUint64(2, true);
+
+// Test emitted declarations files
+const w = 12n; // should emit as const w = 12n
+const x = -12n; // should emit as const x = -12n
+const y: 12n = 12n; // should emit type 12n
+let z = 12n; // should emit type bigint in declaration file
\ No newline at end of file