diff --git a/src/core/asm.c b/src/core/asm.c
index ec90b02c..da206d0d 100644
--- a/src/core/asm.c
+++ b/src/core/asm.c
@@ -294,7 +294,7 @@ static int32_t doarg_1(
                         ret = dst_unwrap_integer(result);
                     }
                 } else {
-                    dst_asm_errorv(a, dst_formatc("unknown name %q", x));
+                    dst_asm_errorv(a, dst_formatc("unknown name %v", x));
                 }
             } else if (argtype == DST_OAT_TYPE || argtype == DST_OAT_SIMPLETYPE) {
                 const TypeAlias *alias = dst_strbinsearch(
@@ -305,7 +305,7 @@ static int32_t doarg_1(
                 if (alias) {
                     ret = alias->mask;
                 } else {
-                    dst_asm_errorv(a, dst_formatc("unknown type %q", x));
+                    dst_asm_errorv(a, dst_formatc("unknown type %v", x));
                 }
             } else {
                 goto error;
@@ -314,7 +314,7 @@ static int32_t doarg_1(
                 /* Add a new env */
                 ret = dst_asm_addenv(a, x);
                 if (ret < -1) {
-                    dst_asm_errorv(a, dst_formatc("unknown environment %q", x));
+                    dst_asm_errorv(a, dst_formatc("unknown environment %v", x));
                 }
             }
             break;
diff --git a/src/core/core.dst b/src/core/core.dst
index 350a6e66..dbd81e56 100644
--- a/src/core/core.dst
+++ b/src/core/core.dst
@@ -48,6 +48,12 @@
   [name & more]
   (apply1 tuple (array.concat @['def name :private] more)))
 
+(defmacro defasm
+  "Define a function using assembly"
+  [name & body]
+  (def tab (apply1 table body))
+  (tuple 'def name (tuple asm (tuple 'quote tab))))
+
 # Basic predicates
 (defn even? [x] (== 0 (% x 2)))
 (defn odd? [x] (not= 0 (% x 2)))