diff --git a/README.md b/README.md
index bc26ee92..5be0f2f5 100644
--- a/README.md
+++ b/README.md
@@ -86,7 +86,7 @@ use reflection.
 1. Run `goverter`:
 
     ```bash
-    $ go run github.com/jmattheis/goverter/cmd/goverter@v0.17.2 ./
+    $ go run github.com/jmattheis/goverter/cmd/goverter@v0.17.3 ./
     ```
 
     See [Installation](https://goverter.jmattheis.de/#/install) for more information.
diff --git a/runner_test.go b/runner_test.go
index ea3eeaba..9aec6fda 100644
--- a/runner_test.go
+++ b/runner_test.go
@@ -94,7 +94,9 @@ func TestScenario(t *testing.T) {
 			require.Equal(t, scenario.Success, string(body))
 			require.NoError(t, compile(genFile), "generated converter doesn't build")
 		})
-		clearDir(execDir)
+		if os.Getenv("SKIP_CLEAN") != "true" {
+			clearDir(execDir)
+		}
 	}
 }
 
diff --git a/scenario/interface_complex.yml b/scenario/interface_complex.yml
new file mode 100644
index 00000000..edc90f7f
--- /dev/null
+++ b/scenario/interface_complex.yml
@@ -0,0 +1,55 @@
+input:
+    input.go: |
+        package structs
+
+        import "io"
+
+        // goverter:converter
+        // goverter:extend ConvertInterface
+        type Converter interface {
+            Convert(source map[string]interface {
+                io.Reader
+                Test() bool
+            }) map[string]interface {
+                io.Writer
+                Test() bool
+            }
+        }
+
+        func ConvertInterface(x interface {
+            io.Reader
+            Test() bool
+        }) interface {
+            io.Writer
+            Test() bool
+        } {
+            return nil
+        }
+success: |
+    // Code generated by github.com/jmattheis/goverter, DO NOT EDIT.
+
+    package generated
+
+    import (
+    	execution "github.com/jmattheis/goverter/execution"
+    	"io"
+    )
+
+    type ConverterImpl struct{}
+
+    func (c *ConverterImpl) Convert(source map[string]interface {
+    	io.Reader
+    	Test() bool
+    }) map[string]interface {
+    	io.Writer
+    	Test() bool
+    } {
+    	mapStringUnknown := make(map[string]interface {
+    		io.Writer
+    		Test() bool
+    	}, len(source))
+    	for key, value := range source {
+    		mapStringUnknown[key] = execution.ConvertInterface(value)
+    	}
+    	return mapStringUnknown
+    }
diff --git a/scenario/interface_embed.yml b/scenario/interface_embed.yml
new file mode 100644
index 00000000..0c47810c
--- /dev/null
+++ b/scenario/interface_embed.yml
@@ -0,0 +1,40 @@
+input:
+    input.go: |
+        package structs
+
+        import "io"
+
+        // goverter:converter
+        // goverter:extend ConvertInterface
+        type Converter interface {
+            Convert(source map[string]interface{ io.Reader }) map[string]interface{ io.Writer }
+        }
+
+        func ConvertInterface(x interface{io.Reader}) interface{io.Writer} {
+            return nil
+        }
+success: |
+    // Code generated by github.com/jmattheis/goverter, DO NOT EDIT.
+
+    package generated
+
+    import (
+    	execution "github.com/jmattheis/goverter/execution"
+    	"io"
+    )
+
+    type ConverterImpl struct{}
+
+    func (c *ConverterImpl) Convert(source map[string]interface {
+    	io.Reader
+    }) map[string]interface {
+    	io.Writer
+    } {
+    	mapStringUnknown := make(map[string]interface {
+    		io.Writer
+    	}, len(source))
+    	for key, value := range source {
+    		mapStringUnknown[key] = execution.ConvertInterface(value)
+    	}
+    	return mapStringUnknown
+    }
diff --git a/scenario/interface_empty.yml b/scenario/interface_empty.yml
new file mode 100644
index 00000000..7fe741a3
--- /dev/null
+++ b/scenario/interface_empty.yml
@@ -0,0 +1,29 @@
+input:
+    input.go: |
+        package structs
+
+        // goverter:converter
+        // goverter:extend ConvertInterface
+        type Converter interface {
+            Convert(source map[string]interface{}) map[string]interface{}
+        }
+
+        func ConvertInterface(x interface{}) interface{} {
+            return nil
+        }
+success: |
+    // Code generated by github.com/jmattheis/goverter, DO NOT EDIT.
+
+    package generated
+
+    import execution "github.com/jmattheis/goverter/execution"
+
+    type ConverterImpl struct{}
+
+    func (c *ConverterImpl) Convert(source map[string]interface{}) map[string]interface{} {
+    	mapStringUnknown := make(map[string]interface{}, len(source))
+    	for key, value := range source {
+    		mapStringUnknown[key] = execution.ConvertInterface(value)
+    	}
+    	return mapStringUnknown
+    }
diff --git a/scenario/interface_methods.yml b/scenario/interface_methods.yml
new file mode 100644
index 00000000..7714048f
--- /dev/null
+++ b/scenario/interface_methods.yml
@@ -0,0 +1,39 @@
+input:
+    input.go: |
+        package structs
+
+        // goverter:converter
+        // goverter:extend ConvertInterface
+        type Converter interface {
+            Convert(source map[string]interface {
+                Test(x bool) (l string, err error)
+            }) map[string]interface{ Test2() }
+        }
+
+        func ConvertInterface(x interface {
+            Test(x bool) (l string, err error)
+        }) interface{ Test2() } {
+            return nil
+        }
+success: |
+    // Code generated by github.com/jmattheis/goverter, DO NOT EDIT.
+
+    package generated
+
+    import execution "github.com/jmattheis/goverter/execution"
+
+    type ConverterImpl struct{}
+
+    func (c *ConverterImpl) Convert(source map[string]interface {
+    	Test(bool) (string, error)
+    }) map[string]interface {
+    	Test2()
+    } {
+    	mapStringUnknown := make(map[string]interface {
+    		Test2()
+    	}, len(source))
+    	for key, value := range source {
+    		mapStringUnknown[key] = execution.ConvertInterface(value)
+    	}
+    	return mapStringUnknown
+    }
diff --git a/xtype/type.go b/xtype/type.go
index b12e7409..27215813 100644
--- a/xtype/type.go
+++ b/xtype/type.go
@@ -264,10 +264,46 @@ func toCode(t types.Type) *jen.Statement {
 		return toCodeBasic(cast.Kind())
 	case *types.Struct:
 		return toCodeStruct(cast)
+	case *types.Interface:
+		return toCodeInterface(cast)
 	}
 	panic("unsupported type " + t.String())
 }
 
+func toCodeInterface(t *types.Interface) *jen.Statement {
+	content := []jen.Code{}
+	for i := 0; i < t.NumEmbeddeds(); i++ {
+		content = append(content, toCode(t.EmbeddedType(i)))
+	}
+
+	for i := 0; i < t.NumExplicitMethods(); i++ {
+		method := t.ExplicitMethod(i)
+		content = append(content, toCodeFunc(method))
+	}
+
+	return jen.Interface(content...)
+}
+
+func toCodeFunc(t *types.Func) *jen.Statement {
+	sig := t.Type().(*types.Signature)
+	return toCodeSignature(t.Name(), sig)
+}
+
+func toCodeSignature(name string, t *types.Signature) *jen.Statement {
+	jenParams := []jen.Code{}
+	params := t.Params()
+	for i := 0; i < params.Len(); i++ {
+		jenParams = append(jenParams, toCode(params.At(i).Type()))
+	}
+
+	jenResults := []jen.Code{}
+	results := t.Results()
+	for i := 0; i < results.Len(); i++ {
+		jenResults = append(jenResults, toCode(results.At(i).Type()))
+	}
+	return jen.Id(name).Params(jenParams...).Params(jenResults...)
+}
+
 func toCodeNamed(t *types.Named) *jen.Statement {
 	var name *jen.Statement
 	if t.Obj().Pkg() == nil {