diff --git a/src/tools/imgtool/charconv.cpp b/src/tools/imgtool/charconv.cpp
index 6a7a500a1cc..387d646f006 100644
--- a/src/tools/imgtool/charconv.cpp
+++ b/src/tools/imgtool/charconv.cpp
@@ -69,7 +69,7 @@ void imgtool::simple_charconverter::from_utf8(std::ostream &dest, const char *sr
 	std::string normalized_src = normalize_unicode(src, src_length, m_norm);
 
 	auto iter = normalized_src.begin();
-	while(iter != normalized_src.end())
+	while (iter != normalized_src.end())
 	{
 		// get the next character
 		char32_t ch;