diff --git a/matlab/ols/parse_ols_style_equation.m b/matlab/ols/parse_ols_style_equation.m
index a1f1160a2..43acee2aa 100644
--- a/matlab/ols/parse_ols_style_equation.m
+++ b/matlab/ols/parse_ols_style_equation.m
@@ -60,7 +60,7 @@ if ~strcmp(ast.AST.arg1.node_type, 'VariableNode') ...
     parsing_error('expecting Variable or UnaryOp on LHS', line);
 else
     if ~isOlsVar(ds, ast.AST.arg1) || ~isBaseVarLagEqualToZero(ast.AST.arg1)
-        parsing_error('the lhs of the equation must be an Variable or UnaryOp with lag == 0 that exists in the dataset', line);
+        parsing_error('the LHS of the equation must be an Variable or UnaryOp with lag == 0 that exists in the dataset', line);
     end
 end