diff --git a/src/passes/01-parser/cameligo/AST.ml b/src/passes/01-parser/cameligo/AST.ml
index c39a54de5..76654aac3 100644
--- a/src/passes/01-parser/cameligo/AST.ml
+++ b/src/passes/01-parser/cameligo/AST.ml
@@ -400,6 +400,10 @@ and cond_expr = {
   ifnot    : expr
 }
 
+(* Code injection.  Note how the field [language] wraps a region in
+   another: the outermost region covers the header "[%<language>" and
+   the innermost covers the <language>. *)
+
 and code_inj = {
   language : string reg reg;
   code     : expr;
diff --git a/src/passes/01-parser/cameligo/Parser.mly b/src/passes/01-parser/cameligo/Parser.mly
index de79c2854..807bc6dd3 100644
--- a/src/passes/01-parser/cameligo/Parser.mly
+++ b/src/passes/01-parser/cameligo/Parser.mly
@@ -121,11 +121,10 @@ type_decl:
   "type" type_name "=" type_expr {
     Scoping.check_reserved_name $2;
     let region = cover $1 (type_expr_to_region $4) in
-    let value = {
-      kwd_type   = $1;
-      name       = $2;
-      eq         = $3;
-      type_expr  = $4}
+    let value  = {kwd_type  = $1;
+                  name      = $2;
+                  eq        = $3;
+                  type_expr = $4}
     in {region; value} }
 
 type_expr:
@@ -710,6 +709,6 @@ seq_expr:
 
 code_inj:
   "<lang>" expr "]" {
-    let region   = cover $1.region $3
-    and value    = {language=$1; code=$2; rbracket=$3}
+    let region = cover $1.region $3
+    and value  = {language=$1; code=$2; rbracket=$3}
     in {region; value} }
diff --git a/src/passes/01-parser/pascaligo/AST.ml b/src/passes/01-parser/pascaligo/AST.ml
index f5ab7c61c..21c1d9b12 100644
--- a/src/passes/01-parser/pascaligo/AST.ml
+++ b/src/passes/01-parser/pascaligo/AST.ml
@@ -426,6 +426,10 @@ and for_collect = {
   block      : block reg
 }
 
+(* Code injection.  Note how the field [language] wraps a region in
+   another: the outermost region covers the header "[%<language>" and
+   the innermost covers the <language>. *)
+
 and code_inj = {
   language : string reg reg;
   code     : expr;