diff --git a/tests/cases/compiler/declarationEmitInferedTypeAlias1.ts b/tests/cases/compiler/declarationEmitInferedTypeAlias1.ts
new file mode 100644
index 00000000000..2e30797e515
--- /dev/null
+++ b/tests/cases/compiler/declarationEmitInferedTypeAlias1.ts
@@ -0,0 +1,13 @@
+// @declaration: true
+// @skipDefaultLibCheck: true
+
+// @Filename: 0.ts
+{
+    type Data = string | boolean;
+    let obj: Data = true;
+}
+export { }
+
+// @Filename: 1.ts
+let v = "str" || true;
+export { v }
\ No newline at end of file
diff --git a/tests/cases/compiler/declarationEmitInferedTypeAlias2.ts b/tests/cases/compiler/declarationEmitInferedTypeAlias2.ts
new file mode 100644
index 00000000000..2a4e4e73b8d
--- /dev/null
+++ b/tests/cases/compiler/declarationEmitInferedTypeAlias2.ts
@@ -0,0 +1,16 @@
+// @declaration: true
+// @skipDefaultLibCheck: true
+
+// @Filename: 0.ts
+{
+    type Data = string | boolean;
+    let obj: Data = true;
+}
+export { }
+
+// @Filename: 1.ts
+let v = "str" || true;
+function bar () {
+    return v;
+}
+export { v, bar }
\ No newline at end of file
diff --git a/tests/cases/compiler/declarationEmitInferedTypeAlias3.ts b/tests/cases/compiler/declarationEmitInferedTypeAlias3.ts
new file mode 100644
index 00000000000..c7ba5168655
--- /dev/null
+++ b/tests/cases/compiler/declarationEmitInferedTypeAlias3.ts
@@ -0,0 +1,13 @@
+// @declaration: true
+// @skipDefaultLibCheck: true
+
+// @Filename: 0.ts
+{
+    type Data = string | boolean;
+    let obj: Data = true;
+}
+export { }
+
+// @Filename: 1.ts
+var x = "hi" || 5;
+export default x;
\ No newline at end of file
diff --git a/tests/cases/compiler/declarationEmitInferedTypeAlias4.ts b/tests/cases/compiler/declarationEmitInferedTypeAlias4.ts
new file mode 100644
index 00000000000..d9c6b75912b
--- /dev/null
+++ b/tests/cases/compiler/declarationEmitInferedTypeAlias4.ts
@@ -0,0 +1,7 @@
+// @declaration: true
+
+function f<A>() {
+    type Foo<T> = T | { x: Foo<T> };
+    var x: Foo<A[]>;
+    return x;
+}
\ No newline at end of file
diff --git a/tests/cases/compiler/declarationEmitInferedTypeAlias5.ts b/tests/cases/compiler/declarationEmitInferedTypeAlias5.ts
new file mode 100644
index 00000000000..787847aecb0
--- /dev/null
+++ b/tests/cases/compiler/declarationEmitInferedTypeAlias5.ts
@@ -0,0 +1,12 @@
+// @declaration: true
+// @skipDefaultLibCheck: true
+
+// @Filename: 0.ts
+export type Data = string | boolean;
+let obj: Data = true;
+
+// @Filename: 1.ts
+import * as Z from "./0"
+//let v2: Z.Data;
+let v = "str" || true;
+export { v }
\ No newline at end of file
diff --git a/tests/cases/compiler/declarationEmitInferedTypeAlias6.ts b/tests/cases/compiler/declarationEmitInferedTypeAlias6.ts
new file mode 100644
index 00000000000..2e30797e515
--- /dev/null
+++ b/tests/cases/compiler/declarationEmitInferedTypeAlias6.ts
@@ -0,0 +1,13 @@
+// @declaration: true
+// @skipDefaultLibCheck: true
+
+// @Filename: 0.ts
+{
+    type Data = string | boolean;
+    let obj: Data = true;
+}
+export { }
+
+// @Filename: 1.ts
+let v = "str" || true;
+export { v }
\ No newline at end of file
diff --git a/tests/cases/compiler/declarationEmitInferedTypeAlias7.ts b/tests/cases/compiler/declarationEmitInferedTypeAlias7.ts
new file mode 100644
index 00000000000..690814f3667
--- /dev/null
+++ b/tests/cases/compiler/declarationEmitInferedTypeAlias7.ts
@@ -0,0 +1,10 @@
+// @declaration: true
+// @skipDefaultLibCheck: true
+
+// @Filename: 0.ts
+export type Data = string | boolean;
+let obj: Data = true;
+
+// @Filename: 1.ts
+let v = "str" || true;
+export { v }
\ No newline at end of file
diff --git a/tests/cases/compiler/declarationEmitInferedTypeAlias8.ts b/tests/cases/compiler/declarationEmitInferedTypeAlias8.ts
new file mode 100644
index 00000000000..20c5e5da2fb
--- /dev/null
+++ b/tests/cases/compiler/declarationEmitInferedTypeAlias8.ts
@@ -0,0 +1,8 @@
+// @declaration: true
+
+type Foo<T> = T | { x: Foo<T> };
+var x: Foo<number[]>;
+
+function returnSomeGlobalValue() {
+    return x;
+}
\ No newline at end of file
diff --git a/tests/cases/compiler/declarationEmitInferedTypeAlias9.ts b/tests/cases/compiler/declarationEmitInferedTypeAlias9.ts
new file mode 100644
index 00000000000..f346cf27e1c
--- /dev/null
+++ b/tests/cases/compiler/declarationEmitInferedTypeAlias9.ts
@@ -0,0 +1,8 @@
+// @declaration: true
+
+type Foo<T> = T | { x: Foo<T> };
+var x: Foo<number[]>;
+
+export function returnSomeGlobalValue() {
+    return x;
+}
\ No newline at end of file