diff --git a/tests/baselines/reference/genericFunctionParameters.js b/tests/baselines/reference/genericFunctionParameters.js
new file mode 100644
index 00000000000..55f4196e77b
--- /dev/null
+++ b/tests/baselines/reference/genericFunctionParameters.js
@@ -0,0 +1,34 @@
+//// [genericFunctionParameters.ts]
+declare function f1<T>(cb: <S>(x: S) => T): T;
+declare function f2<T>(cb: <S extends number>(x: S) => T): T;
+declare function f3<T>(cb: <S extends Array<S>>(x: S) => T): T;
+
+let x1 = f1(x => x);  // {}
+let x2 = f2(x => x);  // number
+let x3 = f3(x => x);  // Array<any>
+
+// Repro from #19345
+
+declare const s: <R>(go: <S>(ops: { init(): S; }) => R) => R;
+const x = s(a => a.init());  // x is any, should have been {}
+
+
+//// [genericFunctionParameters.js]
+"use strict";
+var x1 = f1(function (x) { return x; }); // {}
+var x2 = f2(function (x) { return x; }); // number
+var x3 = f3(function (x) { return x; }); // Array<any>
+var x = s(function (a) { return a.init(); }); // x is any, should have been {}
+
+
+//// [genericFunctionParameters.d.ts]
+declare function f1<T>(cb: <S>(x: S) => T): T;
+declare function f2<T>(cb: <S extends number>(x: S) => T): T;
+declare function f3<T>(cb: <S extends Array<S>>(x: S) => T): T;
+declare let x1: {};
+declare let x2: number;
+declare let x3: any[];
+declare const s: <R>(go: <S>(ops: {
+    init(): S;
+}) => R) => R;
+declare const x: {};
diff --git a/tests/baselines/reference/genericFunctionParameters.symbols b/tests/baselines/reference/genericFunctionParameters.symbols
new file mode 100644
index 00000000000..c5955949289
--- /dev/null
+++ b/tests/baselines/reference/genericFunctionParameters.symbols
@@ -0,0 +1,72 @@
+=== tests/cases/conformance/types/typeRelationships/typeInference/genericFunctionParameters.ts ===
+declare function f1<T>(cb: <S>(x: S) => T): T;
+>f1 : Symbol(f1, Decl(genericFunctionParameters.ts, 0, 0))
+>T : Symbol(T, Decl(genericFunctionParameters.ts, 0, 20))
+>cb : Symbol(cb, Decl(genericFunctionParameters.ts, 0, 23))
+>S : Symbol(S, Decl(genericFunctionParameters.ts, 0, 28))
+>x : Symbol(x, Decl(genericFunctionParameters.ts, 0, 31))
+>S : Symbol(S, Decl(genericFunctionParameters.ts, 0, 28))
+>T : Symbol(T, Decl(genericFunctionParameters.ts, 0, 20))
+>T : Symbol(T, Decl(genericFunctionParameters.ts, 0, 20))
+
+declare function f2<T>(cb: <S extends number>(x: S) => T): T;
+>f2 : Symbol(f2, Decl(genericFunctionParameters.ts, 0, 46))
+>T : Symbol(T, Decl(genericFunctionParameters.ts, 1, 20))
+>cb : Symbol(cb, Decl(genericFunctionParameters.ts, 1, 23))
+>S : Symbol(S, Decl(genericFunctionParameters.ts, 1, 28))
+>x : Symbol(x, Decl(genericFunctionParameters.ts, 1, 46))
+>S : Symbol(S, Decl(genericFunctionParameters.ts, 1, 28))
+>T : Symbol(T, Decl(genericFunctionParameters.ts, 1, 20))
+>T : Symbol(T, Decl(genericFunctionParameters.ts, 1, 20))
+
+declare function f3<T>(cb: <S extends Array<S>>(x: S) => T): T;
+>f3 : Symbol(f3, Decl(genericFunctionParameters.ts, 1, 61))
+>T : Symbol(T, Decl(genericFunctionParameters.ts, 2, 20))
+>cb : Symbol(cb, Decl(genericFunctionParameters.ts, 2, 23))
+>S : Symbol(S, Decl(genericFunctionParameters.ts, 2, 28))
+>Array : Symbol(Array, Decl(lib.d.ts, --, --), Decl(lib.d.ts, --, --))
+>S : Symbol(S, Decl(genericFunctionParameters.ts, 2, 28))
+>x : Symbol(x, Decl(genericFunctionParameters.ts, 2, 48))
+>S : Symbol(S, Decl(genericFunctionParameters.ts, 2, 28))
+>T : Symbol(T, Decl(genericFunctionParameters.ts, 2, 20))
+>T : Symbol(T, Decl(genericFunctionParameters.ts, 2, 20))
+
+let x1 = f1(x => x);  // {}
+>x1 : Symbol(x1, Decl(genericFunctionParameters.ts, 4, 3))
+>f1 : Symbol(f1, Decl(genericFunctionParameters.ts, 0, 0))
+>x : Symbol(x, Decl(genericFunctionParameters.ts, 4, 12))
+>x : Symbol(x, Decl(genericFunctionParameters.ts, 4, 12))
+
+let x2 = f2(x => x);  // number
+>x2 : Symbol(x2, Decl(genericFunctionParameters.ts, 5, 3))
+>f2 : Symbol(f2, Decl(genericFunctionParameters.ts, 0, 46))
+>x : Symbol(x, Decl(genericFunctionParameters.ts, 5, 12))
+>x : Symbol(x, Decl(genericFunctionParameters.ts, 5, 12))
+
+let x3 = f3(x => x);  // Array<any>
+>x3 : Symbol(x3, Decl(genericFunctionParameters.ts, 6, 3))
+>f3 : Symbol(f3, Decl(genericFunctionParameters.ts, 1, 61))
+>x : Symbol(x, Decl(genericFunctionParameters.ts, 6, 12))
+>x : Symbol(x, Decl(genericFunctionParameters.ts, 6, 12))
+
+// Repro from #19345
+
+declare const s: <R>(go: <S>(ops: { init(): S; }) => R) => R;
+>s : Symbol(s, Decl(genericFunctionParameters.ts, 10, 13))
+>R : Symbol(R, Decl(genericFunctionParameters.ts, 10, 18))
+>go : Symbol(go, Decl(genericFunctionParameters.ts, 10, 21))
+>S : Symbol(S, Decl(genericFunctionParameters.ts, 10, 26))
+>ops : Symbol(ops, Decl(genericFunctionParameters.ts, 10, 29))
+>init : Symbol(init, Decl(genericFunctionParameters.ts, 10, 35))
+>S : Symbol(S, Decl(genericFunctionParameters.ts, 10, 26))
+>R : Symbol(R, Decl(genericFunctionParameters.ts, 10, 18))
+>R : Symbol(R, Decl(genericFunctionParameters.ts, 10, 18))
+
+const x = s(a => a.init());  // x is any, should have been {}
+>x : Symbol(x, Decl(genericFunctionParameters.ts, 11, 5))
+>s : Symbol(s, Decl(genericFunctionParameters.ts, 10, 13))
+>a : Symbol(a, Decl(genericFunctionParameters.ts, 11, 12))
+>a.init : Symbol(init, Decl(genericFunctionParameters.ts, 10, 35))
+>a : Symbol(a, Decl(genericFunctionParameters.ts, 11, 12))
+>init : Symbol(init, Decl(genericFunctionParameters.ts, 10, 35))
+
diff --git a/tests/baselines/reference/genericFunctionParameters.types b/tests/baselines/reference/genericFunctionParameters.types
new file mode 100644
index 00000000000..3ae51c83e12
--- /dev/null
+++ b/tests/baselines/reference/genericFunctionParameters.types
@@ -0,0 +1,81 @@
+=== tests/cases/conformance/types/typeRelationships/typeInference/genericFunctionParameters.ts ===
+declare function f1<T>(cb: <S>(x: S) => T): T;
+>f1 : <T>(cb: <S>(x: S) => T) => T
+>T : T
+>cb : <S>(x: S) => T
+>S : S
+>x : S
+>S : S
+>T : T
+>T : T
+
+declare function f2<T>(cb: <S extends number>(x: S) => T): T;
+>f2 : <T>(cb: <S extends number>(x: S) => T) => T
+>T : T
+>cb : <S extends number>(x: S) => T
+>S : S
+>x : S
+>S : S
+>T : T
+>T : T
+
+declare function f3<T>(cb: <S extends Array<S>>(x: S) => T): T;
+>f3 : <T>(cb: <S extends S[]>(x: S) => T) => T
+>T : T
+>cb : <S extends S[]>(x: S) => T
+>S : S
+>Array : T[]
+>S : S
+>x : S
+>S : S
+>T : T
+>T : T
+
+let x1 = f1(x => x);  // {}
+>x1 : {}
+>f1(x => x) : {}
+>f1 : <T>(cb: <S>(x: S) => T) => T
+>x => x : <S>(x: S) => S
+>x : S
+>x : S
+
+let x2 = f2(x => x);  // number
+>x2 : number
+>f2(x => x) : number
+>f2 : <T>(cb: <S extends number>(x: S) => T) => T
+>x => x : <S extends number>(x: S) => S
+>x : S
+>x : S
+
+let x3 = f3(x => x);  // Array<any>
+>x3 : any[]
+>f3(x => x) : any[]
+>f3 : <T>(cb: <S extends S[]>(x: S) => T) => T
+>x => x : <S extends S[]>(x: S) => S
+>x : S
+>x : S
+
+// Repro from #19345
+
+declare const s: <R>(go: <S>(ops: { init(): S; }) => R) => R;
+>s : <R>(go: <S>(ops: { init(): S; }) => R) => R
+>R : R
+>go : <S>(ops: { init(): S; }) => R
+>S : S
+>ops : { init(): S; }
+>init : () => S
+>S : S
+>R : R
+>R : R
+
+const x = s(a => a.init());  // x is any, should have been {}
+>x : {}
+>s(a => a.init()) : {}
+>s : <R>(go: <S>(ops: { init(): S; }) => R) => R
+>a => a.init() : <S>(a: { init(): S; }) => S
+>a : { init(): S; }
+>a.init() : S
+>a.init : () => S
+>a : { init(): S; }
+>init : () => S
+
diff --git a/tests/cases/conformance/types/typeRelationships/typeInference/genericFunctionParameters.ts b/tests/cases/conformance/types/typeRelationships/typeInference/genericFunctionParameters.ts
new file mode 100644
index 00000000000..e639f6b62b3
--- /dev/null
+++ b/tests/cases/conformance/types/typeRelationships/typeInference/genericFunctionParameters.ts
@@ -0,0 +1,15 @@
+// @strict: true
+// @declaration: true
+
+declare function f1<T>(cb: <S>(x: S) => T): T;
+declare function f2<T>(cb: <S extends number>(x: S) => T): T;
+declare function f3<T>(cb: <S extends Array<S>>(x: S) => T): T;
+
+let x1 = f1(x => x);  // {}
+let x2 = f2(x => x);  // number
+let x3 = f3(x => x);  // Array<any>
+
+// Repro from #19345
+
+declare const s: <R>(go: <S>(ops: { init(): S; }) => R) => R;
+const x = s(a => a.init());  // x is any, should have been {}