diff --git a/Changelog.md b/Changelog.md
index b5e48173c..86e0125af 100644
--- a/Changelog.md
+++ b/Changelog.md
@@ -5,6 +5,7 @@ Features:
 
 Bugfixes:
  * Type checker: string literals that are not valid UTF-8 cannot be converted to string type
+ * Code generator: higher bits in a boolean argument are ignored.
 
 ### 0.4.6 (2016-11-22)
 
diff --git a/libsolidity/codegen/CompilerUtils.cpp b/libsolidity/codegen/CompilerUtils.cpp
index d5361ac6a..ff0f8b9c2 100644
--- a/libsolidity/codegen/CompilerUtils.cpp
+++ b/libsolidity/codegen/CompilerUtils.cpp
@@ -925,6 +925,8 @@ unsigned CompilerUtils::loadFromMemoryHelper(Type const& _type, bool _fromCallda
 		if (leftAligned)
 			m_context << shiftFactor << Instruction::MUL;
 	}
+	if (_fromCalldata && _type.category() == Type::Category::Bool)
+		m_context << Instruction::ISZERO << Instruction::ISZERO;
 
 	return numBytes;
 }