diff --git a/ml.cpp b/ml.cpp
index 2b64e98..a38a1d3 100644
--- a/ml.cpp
+++ b/ml.cpp
@@ -812,7 +812,7 @@ MlValue parse(std::string &s, int &ptr) {
 
 		int save_ptr = ptr;
 		while (isdigit(s[ptr]) || s[ptr] == '.') ptr++;
-		std::string n = s.substr(save_ptr, ptr);
+		std::string n = s.substr(save_ptr, ptr - save_ptr);
 		skip_whitespace(s, ptr);
 
 		if (n.find('.') != std::string::npos)