diff --git a/alib2/src/regexp/RegExpToStringComposer.cpp b/alib2/src/regexp/RegExpToStringComposer.cpp
index 3bb3f12101748816e5e6557a19eac991b38fd5c1..c87e19b0af473882ad5928bcd6dc764c2f15b6d7 100644
--- a/alib2/src/regexp/RegExpToStringComposer.cpp
+++ b/alib2/src/regexp/RegExpToStringComposer.cpp
@@ -45,7 +45,14 @@ void RegExpToStringComposer::Visit(void* userData, const Alternation& alternatio
 }
 
 void RegExpToStringComposer::Visit(void* userData, const Concatenation& concatenation) {
+	std::stringstream &out = *((std::stringstream*) userData);
+
+	bool first = true;
 	for (auto element : concatenation.getElements()) {
+		if(first) 
+			first = false;
+		else
+			out << ' ';
 		const RegExpElement::element_type& object = static_cast<const RegExpElement::element_type&>(*element);
 		object.Accept(userData, *this);
 	}