diff --git a/src/insets/InsetCommandParams.cpp b/src/insets/InsetCommandParams.cpp
index cae982782c..39c7715dc5 100644
--- a/src/insets/InsetCommandParams.cpp
+++ b/src/insets/InsetCommandParams.cpp
@@ -495,12 +495,13 @@ docstring InsetCommandParams::prepareCommand(OutputParams const & runparams,
 	if (handling & ParamInfo::HANDLING_INDEX_ESCAPE) {
 		// Now escape special commands
 		static docstring const quote = from_ascii("\"");
-		static char_type const chars_escape[4] = { '"', '@', '|', '!' };
+		int const nchars_escape = 4;
+		static char_type const chars_escape[nchars_escape] = { '"', '@', '|', '!' };
 
 		if (!result.empty()) {
 			// The characters in chars_name[] need to be changed to a command when
 			// they are LaTeXified.
-			for (int k = 0; k < 4; k++)
+			for (int k = 0; k < nchars_escape; k++)
 				for (size_t i = 0, pos;
 					(pos = result.find(chars_escape[k], i)) != string::npos;
 					i = pos + 2)