diff --git a/libsolidity/analysis/TypeChecker.cpp b/libsolidity/analysis/TypeChecker.cpp
index 28cc69a04..fef0ed27a 100644
--- a/libsolidity/analysis/TypeChecker.cpp
+++ b/libsolidity/analysis/TypeChecker.cpp
@@ -1859,12 +1859,15 @@ void TypeChecker::endVisit(BinaryOperation const& _operation)
 		commonType = builtinResult.get();
 	else if (userDefinedOperatorResult)
 	{
-		solAssert(
-			userDefinedFunctionType->parameterTypes().size() == 2 &&
-			*userDefinedFunctionType->parameterTypes().at(0) ==
-			*userDefinedFunctionType->parameterTypes().at(1)
-		);
-		if (userDefinedFunctionType->returnParameterTypes().size() == 1)
+		if (userDefinedFunctionType->parameterTypes().size() != 2 ||
+			*userDefinedFunctionType->parameterTypes().at(0) != *userDefinedFunctionType->parameterTypes().at(1))
+			m_errorReporter.typeError(
+				5653_error,
+				_operation.location(),
+				"User defined operator " + string(TokenTraits::toString(_operation.getOperator())) +
+				" needs to have two parameters of equal type."
+			);
+		else if (userDefinedFunctionType->returnParameterTypes().size() == 1)
 			commonType = userDefinedFunctionType->parameterTypes().at(0);
 	}
 
diff --git a/test/libsolidity/syntaxTests/operators/custom/operator_with_calldata_parameters.sol b/test/libsolidity/syntaxTests/operators/custom/operator_with_calldata_parameters.sol
index 7b33b691b..811165f31 100644
--- a/test/libsolidity/syntaxTests/operators/custom/operator_with_calldata_parameters.sol
+++ b/test/libsolidity/syntaxTests/operators/custom/operator_with_calldata_parameters.sol
@@ -1,4 +1,12 @@
-using {add as +} for S;
+using {
+    add as +,
+    sub as -,
+    mul as *,
+    div as /,
+    mod as %,
+    unsub as -,
+    bitnot as ~
+} for S;
 
 struct S {
     uint x;
@@ -9,3 +17,54 @@ function add(S calldata, S calldata) pure returns (S calldata r) {
         r := 0
     }
 }
+
+function sub(S calldata, uint) pure returns (S calldata r) {
+    assembly {
+        r := 0
+    }
+}
+
+function mul(S calldata) pure returns (S calldata r) {
+    assembly {
+        r := 0
+    }
+}
+
+function div(S calldata, S calldata) pure returns (uint) {
+    return 0;
+}
+
+function mod(S calldata, S calldata) pure {
+}
+
+function unsub(uint) pure returns (S calldata r) {
+    assembly {
+        r := 0
+    }
+}
+
+function bitnot(S calldata) pure {
+}
+
+function test(S calldata s) pure {
+    s + s;
+    s - s;
+    s * s;
+    s / s;
+    s % s;
+    -s;
+    ~s;
+}
+
+// ----
+// TypeError 1884: (40-43): The function "mul" needs to have two parameters of equal type to be used for the operator *.
+// TypeError 7743: (54-57): The function "div" needs to return exactly one value of type S to be used for the operator /.
+// TypeError 7743: (68-71): The function "mod" needs to return exactly one value of type S to be used for the operator %.
+// TypeError 3100: (82-87): The function "unsub" cannot be bound to the type "struct S storage pointer" because the type cannot be implicitly converted to the first argument of the function ("uint256").
+// TypeError 7743: (98-104): The function "bitnot" needs to return exactly one value of type S to be used for the operator ~.
+// TypeError 5653: (747-752): User defined operator - needs to have two parameters of equal type.
+// TypeError 2271: (758-763): Operator * not compatible with types struct S calldata and struct S calldata. No matching user-defined operator found.
+// TypeError 3841: (769-774): User defined operator / needs to return value of type struct S calldata.
+// TypeError 1208: (780-785): User defined operator % needs to return exactly one value.
+// TypeError 4907: (791-793): Unary operator - cannot be applied to type struct S calldata. No matching user-defined operator found.
+// TypeError 3138: (799-801): User defined operator ~ needs to return exactly one value.
diff --git a/test/libsolidity/syntaxTests/operators/custom/operator_with_storage_parameters.sol b/test/libsolidity/syntaxTests/operators/custom/operator_with_storage_parameters.sol
index d905104c8..c7d6b4616 100644
--- a/test/libsolidity/syntaxTests/operators/custom/operator_with_storage_parameters.sol
+++ b/test/libsolidity/syntaxTests/operators/custom/operator_with_storage_parameters.sol
@@ -1,4 +1,12 @@
-using {add as +} for S;
+using {
+    add as +,
+    sub as -,
+    mul as *,
+    div as /,
+    mod as %,
+    unsub as -,
+    bitnot as ~
+} for S;
 
 struct S {
     uint x;
@@ -8,11 +16,52 @@ function add(S storage a, S storage) pure returns (S storage) {
     return a;
 }
 
+function sub(S storage a, uint) pure returns (S storage) {
+    return a;
+}
+
+function mul(S storage a) pure returns (S storage) {
+    return a;
+}
+
+function div(S storage a, S storage) pure returns (uint) {
+    return 0;
+}
+
+function mod(S storage a, S storage) pure {
+}
+
+function unsub(S storage a) pure {
+}
+
+function bitnot(S storage a, S storage) pure returns (S storage) {
+    return a;
+}
+
 contract C {
     S a;
     S b;
 
     function test() public view {
         a + b;
+        a - b;
+        a * b;
+        a / b;
+        a % b;
+        -a;
+        ~a;
     }
 }
+// ----
+// TypeError 1884: (40-43): The function "mul" needs to have two parameters of equal type to be used for the operator *.
+// TypeError 7743: (54-57): The function "div" needs to return exactly one value of type S to be used for the operator /.
+// TypeError 7743: (68-71): The function "mod" needs to return exactly one value of type S to be used for the operator %.
+// TypeError 7743: (82-87): The function "unsub" needs to return exactly one value of type S to be used for the operator -.
+// TypeError 1147: (98-104): The function "bitnot" needs to have exactly one parameter to be used for the operator ~.
+// TypeError 5653: (707-712): User defined operator - needs to have two parameters of equal type.
+// TypeError 3841: (707-712): User defined operator - needs to return value of type struct S storage ref.
+// TypeError 2271: (722-727): Operator * not compatible with types struct S storage ref and struct S storage ref. No matching user-defined operator found.
+// TypeError 3841: (737-742): User defined operator / needs to return value of type struct S storage pointer.
+// TypeError 1208: (752-757): User defined operator % needs to return exactly one value.
+// TypeError 3138: (767-769): User defined operator - needs to return exactly one value.
+// TypeError 4907: (779-781): Unary operator ~ cannot be applied to type struct S storage ref. No matching user-defined operator found.