diff --git a/libsolidity/analysis/TypeChecker.cpp b/libsolidity/analysis/TypeChecker.cpp
index 87951003a..3456958c7 100644
--- a/libsolidity/analysis/TypeChecker.cpp
+++ b/libsolidity/analysis/TypeChecker.cpp
@@ -463,6 +463,9 @@ bool TypeChecker::visit(FunctionDefinition const& _function)
 			typeError(_function.location(), "Functions in interfaces cannot have an implementation.");
 		_function.body().accept(*this);
 	}
+	if (_function.visibility() < FunctionDefinition::Visibility::Public)
+		if (m_scope->contractKind() == ContractDefinition::ContractKind::Interface)
+			typeError(_function.location(), "Functions in interfaces cannot be internal or private.");
 	if (_function.isConstructor())
 		if (m_scope->contractKind() == ContractDefinition::ContractKind::Interface)
 			typeError(_function.location(), "Constructor cannot be defined in interfaces.");
diff --git a/test/libsolidity/SolidityNameAndTypeResolution.cpp b/test/libsolidity/SolidityNameAndTypeResolution.cpp
index 2a0f342cc..c002fd3e8 100644
--- a/test/libsolidity/SolidityNameAndTypeResolution.cpp
+++ b/test/libsolidity/SolidityNameAndTypeResolution.cpp
@@ -5368,6 +5368,26 @@ BOOST_AUTO_TEST_CASE(interface_function_bodies)
 	CHECK_ERROR(text, TypeError, "Functions in interfaces cannot have an implementation");
 }
 
+BOOST_AUTO_TEST_CASE(interface_function_internal)
+{
+	char const* text = R"(
+		interface I {
+			function f() internal;
+		}
+	)";
+	CHECK_ERROR(text, TypeError, "Functions in interfaces cannot be internal or private.");
+}
+
+BOOST_AUTO_TEST_CASE(interface_function_private)
+{
+	char const* text = R"(
+		interface I {
+			function f() private;
+		}
+	)";
+	CHECK_ERROR(text, TypeError, "Functions in interfaces cannot be internal or private.");
+}
+
 BOOST_AUTO_TEST_CASE(interface_events)
 {
 	char const* text = R"(