diff --git a/source/eaxhla.l b/source/eaxhla.l
index fce35dd..dc14ac9 100644
--- a/source/eaxhla.l
+++ b/source/eaxhla.l
@@ -6,6 +6,7 @@
 identifier [A-z_][A-z0-9_]*
 wsnl       [ \t\r\v\f\n]
 
+%option yylineno
 %%
 
 program{wsnl}+{identifier}{wsnl}+begin{wsnl}+  { return PROGRAM_HEAD; }
diff --git a/source/eaxhla.y b/source/eaxhla.y
index e76ed52..8612fbf 100644
--- a/source/eaxhla.y
+++ b/source/eaxhla.y
@@ -4,7 +4,10 @@
     #include "eaxhla.yy.h"
     #include "assembler.h"
 
-    void yyerror() { ; }
+    void yyerror() {
+        printf("\033[31mError: syntax error at line %d.\033[0m\n", yylineno);
+    }
+
 %}
 
 %union{