diff --git a/ql/src/semmle/go/frameworks/Stdlib.qll b/ql/src/semmle/go/frameworks/Stdlib.qll
index cb5b97e0609..df794f8f073 100644
--- a/ql/src/semmle/go/frameworks/Stdlib.qll
+++ b/ql/src/semmle/go/frameworks/Stdlib.qll
@@ -30,6 +30,7 @@ import semmle.go.frameworks.stdlib.EncodingXml
 import semmle.go.frameworks.stdlib.Html
 import semmle.go.frameworks.stdlib.HtmlTemplate
 import semmle.go.frameworks.stdlib.Errors
+import semmle.go.frameworks.stdlib.Expvar
 import semmle.go.frameworks.stdlib.Path
 import semmle.go.frameworks.stdlib.PathFilepath
 import semmle.go.frameworks.stdlib.Reflect
diff --git a/ql/src/semmle/go/frameworks/stdlib/Expvar.qll b/ql/src/semmle/go/frameworks/stdlib/Expvar.qll
new file mode 100644
index 00000000000..a2650c9db35
--- /dev/null
+++ b/ql/src/semmle/go/frameworks/stdlib/Expvar.qll
@@ -0,0 +1,51 @@
+/**
+ * Provides classes modeling security-relevant aspects of the `expvar` package.
+ */
+
+import go
+
+/** Provides models of commonly used functions in the `expvar` package. */
+module Expvar {
+  private class MethodModels extends TaintTracking::FunctionModel, Method {
+    FunctionInput inp;
+    FunctionOutput outp;
+
+    MethodModels() {
+      // signature: func (Func).Value() interface{}
+      this.hasQualifiedName("expvar", "Func", "Value") and
+      (inp.isReceiver() and outp.isResult())
+      or
+      // signature: func (*Map).Get(key string) Var
+      this.hasQualifiedName("expvar", "Map", "Get") and
+      (inp.isReceiver() and outp.isResult())
+      or
+      // signature: func (*Map).Set(key string, av Var)
+      this.hasQualifiedName("expvar", "Map", "Set") and
+      (inp.isParameter(_) and outp.isReceiver())
+      or
+      // signature: func (*Map).String() string
+      this.hasQualifiedName("expvar", "Map", "String") and
+      (inp.isReceiver() and outp.isResult())
+      or
+      // signature: func (*String).Set(value string)
+      this.hasQualifiedName("expvar", "String", "Set") and
+      (inp.isParameter(0) and outp.isReceiver())
+      or
+      // signature: func (*String).String() string
+      this.hasQualifiedName("expvar", "String", "String") and
+      (inp.isReceiver() and outp.isResult())
+      or
+      // signature: func (*String).Value() string
+      this.hasQualifiedName("expvar", "String", "Value") and
+      (inp.isReceiver() and outp.isResult())
+      or
+      // signature: func (Var).String() string
+      this.implements("expvar", "Var", "String") and
+      (inp.isReceiver() and outp.isResult())
+    }
+
+    override predicate hasTaintFlow(FunctionInput input, FunctionOutput output) {
+      input = inp and output = outp
+    }
+  }
+}
diff --git a/ql/test/library-tests/semmle/go/frameworks/StdlibTaintFlow/Expvar.go b/ql/test/library-tests/semmle/go/frameworks/StdlibTaintFlow/Expvar.go
new file mode 100644
index 00000000000..429612f221b
--- /dev/null
+++ b/ql/test/library-tests/semmle/go/frameworks/StdlibTaintFlow/Expvar.go
@@ -0,0 +1,110 @@
+// Code generated by https://github.com/gagliardetto/codebox. DO NOT EDIT.
+
+package main
+
+import "expvar"
+
+func TaintStepTest_ExpvarFuncValue_B0I0O0(sourceCQL interface{}) interface{} {
+	fromFunc656 := sourceCQL.(expvar.Func)
+	intoInterface414 := fromFunc656.Value()
+	return intoInterface414
+}
+
+func TaintStepTest_ExpvarMapGet_B0I0O0(sourceCQL interface{}) interface{} {
+	fromMap518 := sourceCQL.(expvar.Map)
+	intoVar650 := fromMap518.Get("")
+	return intoVar650
+}
+
+func TaintStepTest_ExpvarMapSet_B0I0O0(sourceCQL interface{}) interface{} {
+	fromString784 := sourceCQL.(string)
+	var intoMap957 expvar.Map
+	intoMap957.Set(fromString784, nil)
+	return intoMap957
+}
+
+func TaintStepTest_ExpvarMapSet_B0I1O0(sourceCQL interface{}) interface{} {
+	fromVar520 := sourceCQL.(expvar.Var)
+	var intoMap443 expvar.Map
+	intoMap443.Set("", fromVar520)
+	return intoMap443
+}
+
+func TaintStepTest_ExpvarMapString_B0I0O0(sourceCQL interface{}) interface{} {
+	fromMap127 := sourceCQL.(expvar.Map)
+	intoString483 := fromMap127.String()
+	return intoString483
+}
+
+func TaintStepTest_ExpvarStringSet_B0I0O0(sourceCQL interface{}) interface{} {
+	fromString989 := sourceCQL.(string)
+	var intoString982 expvar.String
+	intoString982.Set(fromString989)
+	return intoString982
+}
+
+func TaintStepTest_ExpvarStringString_B0I0O0(sourceCQL interface{}) interface{} {
+	fromString417 := sourceCQL.(expvar.String)
+	intoString584 := fromString417.String()
+	return intoString584
+}
+
+func TaintStepTest_ExpvarStringValue_B0I0O0(sourceCQL interface{}) interface{} {
+	fromString991 := sourceCQL.(expvar.String)
+	intoString881 := fromString991.Value()
+	return intoString881
+}
+
+func TaintStepTest_ExpvarVarString_B0I0O0(sourceCQL interface{}) interface{} {
+	fromVar186 := sourceCQL.(expvar.Var)
+	intoString284 := fromVar186.String()
+	return intoString284
+}
+
+func RunAllTaints_Expvar() {
+	{
+		source := newSource(0)
+		out := TaintStepTest_ExpvarFuncValue_B0I0O0(source)
+		sink(0, out)
+	}
+	{
+		source := newSource(1)
+		out := TaintStepTest_ExpvarMapGet_B0I0O0(source)
+		sink(1, out)
+	}
+	{
+		source := newSource(2)
+		out := TaintStepTest_ExpvarMapSet_B0I0O0(source)
+		sink(2, out)
+	}
+	{
+		source := newSource(3)
+		out := TaintStepTest_ExpvarMapSet_B0I1O0(source)
+		sink(3, out)
+	}
+	{
+		source := newSource(4)
+		out := TaintStepTest_ExpvarMapString_B0I0O0(source)
+		sink(4, out)
+	}
+	{
+		source := newSource(5)
+		out := TaintStepTest_ExpvarStringSet_B0I0O0(source)
+		sink(5, out)
+	}
+	{
+		source := newSource(6)
+		out := TaintStepTest_ExpvarStringString_B0I0O0(source)
+		sink(6, out)
+	}
+	{
+		source := newSource(7)
+		out := TaintStepTest_ExpvarStringValue_B0I0O0(source)
+		sink(7, out)
+	}
+	{
+		source := newSource(8)
+		out := TaintStepTest_ExpvarVarString_B0I0O0(source)
+		sink(8, out)
+	}
+}