diff --git a/libsolidity/Compiler.cpp b/libsolidity/Compiler.cpp
index ef5680138..43cbc462e 100644
--- a/libsolidity/Compiler.cpp
+++ b/libsolidity/Compiler.cpp
@@ -107,13 +107,7 @@ void ExpressionCompiler::endVisit(UnaryOperation& _unaryOperation)
 		append(eth::Instruction::NOT);
 		break;
 	case Token::BIT_NOT: // ~
-		// ~a modeled as "a xor (0 - 1)" for now
-		append(eth::Instruction::PUSH1);
-		append(1);
-		append(eth::Instruction::PUSH1);
-		append(0);
-		append(eth::Instruction::SUB);
-		append(eth::Instruction::XOR);
+		append(eth::Instruction::BNOT);
 		break;
 	case Token::DELETE: // delete
 		// a -> a xor a (= 0).
@@ -145,7 +139,10 @@ void ExpressionCompiler::endVisit(UnaryOperation& _unaryOperation)
 		// unary add, so basically no-op
 		break;
 	case Token::SUB: // -
-		append(eth::Instruction::NEG);
+		// unary -x translates into "0-x"
+		append(eth::Instruction::PUSH1);
+		append(0);
+		append(eth::Instruction::SUB);
 		break;
 	default:
 		assert(false); // invalid operation
diff --git a/test/solidityCompiler.cpp b/test/solidityCompiler.cpp
index 26bfc7cb6..0d9d59c1c 100644
--- a/test/solidityCompiler.cpp
+++ b/test/solidityCompiler.cpp
@@ -212,11 +212,9 @@ BOOST_AUTO_TEST_CASE(unary_operators)
 					   byte(eth::Instruction::PUSH1), 0x1,
 					   byte(eth::Instruction::SWAP1),
 					   byte(eth::Instruction::SUB),
-					   byte(eth::Instruction::NEG),
-					   byte(eth::Instruction::PUSH1), 0x1,
 					   byte(eth::Instruction::PUSH1), 0x0,
 					   byte(eth::Instruction::SUB),
-					   byte(eth::Instruction::XOR), // bitwise not
+					   byte(eth::Instruction::BNOT),
 					   byte(eth::Instruction::PUSH1), 0x2,
 					   byte(eth::Instruction::EQ),
 					   byte(eth::Instruction::NOT)});