diff --git a/include/tclap/StdOutput.h b/include/tclap/StdOutput.h
index 9dd6d0f..9ceac0c 100644
--- a/include/tclap/StdOutput.h
+++ b/include/tclap/StdOutput.h
@@ -248,10 +248,10 @@ inline void StdOutput::spacePrint( std::ostream& os,
 
 					// trim the length so it doesn't end in middle of a word
 					if ( stringLen == allowedLen )
-						while ( s[stringLen+start] != ' ' && 
+						while ( stringLen >= 0 &&
+								s[stringLen+start] != ' ' && 
 								s[stringLen+start] != ',' &&
-								s[stringLen+start] != '|' &&
-								stringLen >= 0 )
+								s[stringLen+start] != '|' ) 
 							stringLen--;
 	
 					// ok, the word is longer than the line, so just split