diff --git a/Makefile b/Makefile
index 8e0ce1ea..24ecd644 100644
--- a/Makefile
+++ b/Makefile
@@ -4,7 +4,7 @@ build:
 	cd src; \
 	yacc -d parse.y; \
 	lex scan.l
-	gcc -o bin/picrin -I./include src/main.c src/state.c src/gc.c src/pair.c src/port.c src/symbol.c src/value.c src/y.tab.c src/lex.yy.c src/bool.c src/vm.c src/init.c src/number.c
+	gcc -Wall -o bin/picrin -I./include src/main.c src/state.c src/gc.c src/pair.c src/port.c src/symbol.c src/value.c src/y.tab.c src/lex.yy.c src/bool.c src/vm.c src/init.c src/number.c
 
 clean:
 	rm -f src/y.tab.c src/y.tab.h src/lex.yy.c
diff --git a/src/port.c b/src/port.c
index ee31b2f6..e6ddbbb0 100644
--- a/src/port.c
+++ b/src/port.c
@@ -30,9 +30,6 @@ pic_debug(pic_state *pic, pic_value obj)
   case PIC_TT_PROC:
     printf("#<proc %p>", pic_proc_ptr(obj));
     break;
-  default:
-    printf("#<unknown type>");
-    break;
   }
 }
 
diff --git a/src/vm.c b/src/vm.c
index 46215a6c..60bf32c2 100644
--- a/src/vm.c
+++ b/src/vm.c
@@ -149,9 +149,6 @@ print_irep(pic_state *pic, struct pic_irep *irep)
     case OP_STOP:
       puts("OP_STOP");
       break;
-    default:
-      puts("<<unknown>>");
-      break;
     }
   }
 }