diff --git a/antlr/pdp7asm.g4 b/antlr/pdp7asm.g4
index 0ce3397..fb0e291 100644
--- a/antlr/pdp7asm.g4
+++ b/antlr/pdp7asm.g4
@@ -45,6 +45,10 @@ declarations
     ;
 
 declaration
+    : instruction
+    ;
+
+instruction
     : opcode argument+
     ;