diff --git a/lang/m2/comp/chk_expr.c b/lang/m2/comp/chk_expr.c
index bf9c58c34..22d91ea74 100644
--- a/lang/m2/comp/chk_expr.c
+++ b/lang/m2/comp/chk_expr.c
@@ -369,7 +369,7 @@ left->nd_def->df_idf->id_text, left->nd_def->df_value.df_stdname));
 					/* A dynamic array has no explicit
 					   index type
 					*/
-					expp->nd_type = int_type;
+					expp->nd_type = intorcard_type;
 				}
 				else	cstcall(expp, S_MAX);
 				break;
@@ -667,16 +667,19 @@ node_error(expp, "IN operator: type of LHS not compatible with element type of R
 	}
 
 	if (expp->nd_symb == '[') {
-		/* Handle ARRAY selection specially too! */
+		/* Handle ARRAY selection specially too!
+		*/
 		if (tpl->tp_fund != T_ARRAY) {
 			node_error(expp,
 				   "array index not belonging to an ARRAY");
 			return 0;
 		}
-		if (!TstCompat(tpl->next, tpr)) {
+
+		if ((tpl->next && !TstCompat(tpl->next, tpr)) ||
+		    (!tpl->next && !TstCompat(intorcard_type, tpr)) {
 			node_error(expp, "incompatible index type");
-			return 0;
 		}
+
 		expp->nd_type = tpl->arr_elem;
 		return 1;
 	}
diff --git a/lang/m2/comp/declar.g b/lang/m2/comp/declar.g
index b42921fee..abd63d34d 100644
--- a/lang/m2/comp/declar.g
+++ b/lang/m2/comp/declar.g
@@ -61,7 +61,7 @@ ProcedureHeading(struct def **pdf; int type;)
 			/* We already saw a definition of this type
 			   in the definition module.
 			*/
-		  	if (!TstTypeEquiv(tp, df->df_type)) {
+		  	if (!TstProcEquiv(tp, df->df_type)) {
 error("inconsistent procedure declaration for \"%s\"", df->df_idf->id_text); 
 			}
 			FreeType(df->df_type);
diff --git a/lang/m2/comp/typequiv.c b/lang/m2/comp/typequiv.c
index 3054afc35..4c48a3058 100644
--- a/lang/m2/comp/typequiv.c
+++ b/lang/m2/comp/typequiv.c
@@ -95,6 +95,10 @@ TstCompat(tp1, tp2)
 		&&
 		   (tp2 == int_type || tp2 == card_type)
 		)
+	    ||
+		(tp1 == char_type && tp2 == charc_type)
+	    ||
+		(tp2 == char_type && tp1 == charc_type)
 	    ||
 		(  tp2 == intorcard_type
 		&&
diff --git a/lang/m2/comp/walk.c b/lang/m2/comp/walk.c
index 653b6db6f..6324b8beb 100644
--- a/lang/m2/comp/walk.c
+++ b/lang/m2/comp/walk.c
@@ -272,7 +272,7 @@ ExpectBool(nd)
 
 	chk_expr(nd);
 
-	if (nd->nd_type != bool_type) {
+	if (nd->nd_type != bool_type && nd->nd_type != error_type) {
 		node_error(nd, "boolean expression expected");
 	}