diff --git a/Changelog.md b/Changelog.md
index ade9ac869..58604ca24 100644
--- a/Changelog.md
+++ b/Changelog.md
@@ -1,6 +1,7 @@
 ### 0.4.21 (unreleased)
 
 Features:
+ * Type Checker: Disallow uninitialized storage pointers as experimental 0.5.0 feature.
 
 
 Bugfixes:
diff --git a/libsolidity/analysis/TypeChecker.cpp b/libsolidity/analysis/TypeChecker.cpp
index d67142e40..f62ddeb97 100644
--- a/libsolidity/analysis/TypeChecker.cpp
+++ b/libsolidity/analysis/TypeChecker.cpp
@@ -972,7 +972,11 @@ bool TypeChecker::visit(VariableDeclarationStatement const& _statement)
 				string errorText{"Uninitialized storage pointer."};
 				if (varDecl.referenceLocation() == VariableDeclaration::Location::Default)
 					errorText += " Did you mean '<type> memory " + varDecl.name() + "'?";
-				m_errorReporter.warning(varDecl.location(), errorText);
+				solAssert(m_scope, "");
+				if (m_scope->sourceUnit().annotation().experimentalFeatures.count(ExperimentalFeature::V050))
+					m_errorReporter.declarationError(varDecl.location(), errorText);
+				else
+					m_errorReporter.warning(varDecl.location(), errorText);
 			}
 		}
 		else if (dynamic_cast<MappingType const*>(type(varDecl).get()))
diff --git a/test/libsolidity/SolidityNameAndTypeResolution.cpp b/test/libsolidity/SolidityNameAndTypeResolution.cpp
index 315c7c5f8..2b1023120 100644
--- a/test/libsolidity/SolidityNameAndTypeResolution.cpp
+++ b/test/libsolidity/SolidityNameAndTypeResolution.cpp
@@ -3021,6 +3021,20 @@ BOOST_AUTO_TEST_CASE(uninitialized_mapping_array_variable)
 	CHECK_WARNING(sourceCode, "Uninitialized storage pointer");
 }
 
+BOOST_AUTO_TEST_CASE(uninitialized_mapping_array_variable_050)
+{
+	char const* sourceCode = R"(
+		pragma experimental "v0.5.0";
+		contract C {
+			function f() pure public {
+				mapping(uint => uint)[] storage x;
+				x;
+			}
+		}
+	)";
+	CHECK_ERROR(sourceCode, DeclarationError, "Uninitialized storage pointer");
+}
+
 BOOST_AUTO_TEST_CASE(no_delete_on_storage_pointers)
 {
 	char const* sourceCode = R"(
@@ -3320,6 +3334,24 @@ BOOST_AUTO_TEST_CASE(non_initialized_references)
 	CHECK_WARNING(text, "Uninitialized storage pointer");
 }
 
+BOOST_AUTO_TEST_CASE(non_initialized_references_050)
+{
+	char const* text = R"(
+		pragma experimental "v0.5.0";
+		contract c
+		{
+			struct s {
+				uint a;
+			}
+			function f() public {
+				s storage x;
+			}
+		}
+	)";
+
+	CHECK_ERROR(text, DeclarationError, "Uninitialized storage pointer");
+}
+
 BOOST_AUTO_TEST_CASE(keccak256_with_large_integer_constant)
 {
 	char const* text = R"(