diff --git a/src/config/Param.cxx b/src/config/Param.cxx
index a14d18524..bb1962e7d 100644
--- a/src/config/Param.cxx
+++ b/src/config/Param.cxx
@@ -25,9 +25,6 @@
 
 #include <stdexcept>
 
-ConfigParam::ConfigParam(const char *_value, int _line)
-	:value(_value), line(_line) {}
-
 ConfigParam::~ConfigParam()
 {
 	delete next;
diff --git a/src/config/Param.hxx b/src/config/Param.hxx
index 744583b8b..29338dd69 100644
--- a/src/config/Param.hxx
+++ b/src/config/Param.hxx
@@ -48,7 +48,8 @@ struct ConfigParam {
 		:line(_line) {}
 
 	gcc_nonnull_all
-	ConfigParam(const char *_value, int _line=-1);
+	explicit ConfigParam(const char *_value, int _line=-1) noexcept
+		:value(_value), line(_line) {}
 
 	ConfigParam(const ConfigParam &) = delete;