diff --git a/b2/param.c b/b2/param.c
index ef9bf89..64855cc 100644
--- a/b2/param.c
+++ b/b2/param.c
@@ -10,8 +10,10 @@
  */
 
 
+#include <stdlib.h>
 #include <glib.h>
 
+#include "util.h"
 #include "lang.h"
 #include "param.h"
 
@@ -113,3 +115,42 @@ MKOPS(name);
 MKOPS(set);
 MKOPS(abs);
 MKOPS(rel);
+
+
+/* ----- Parameters as general-purpose (string) variables ------------------ */
+
+
+struct param *make_var(const char *name, enum relop op, const char *val)
+{
+	struct param *var;
+
+	var = alloc_type(struct param);
+	var->u.name = unique(name);
+	var->op = op;
+	var->value.u.s = unique(val);
+	var->next = NULL;
+	return var;
+}
+
+
+const char *var_lookup(const struct param *vars, const char *name)
+{
+	while (vars) {
+		if (vars->u.name == name)
+			return vars->value.u.s;
+		vars = vars->next;
+	}
+	return NULL;
+}
+
+
+void free_vars(struct param *vars)
+{
+	struct param *next;
+
+	while (vars) {
+		next = vars->next;
+		free(vars);
+		vars = next;
+	}
+}
diff --git a/b2/param.h b/b2/param.h
index 8369ffd..09561d8 100644
--- a/b2/param.h
+++ b/b2/param.h
@@ -116,4 +116,8 @@ extern const struct param_ops param_ops_set;
 extern const struct param_ops param_ops_abs;
 extern const struct param_ops param_ops_rel;
 
+struct param *make_var(const char *name, enum relop op, const char *val);
+const char *var_lookup(const struct param *vars, const char *name);
+void free_vars(struct param *vars);
+
 #endif /* !PARAM_H */
diff --git a/b2/subex.c b/b2/subex.c
index 7826460..97b8342 100644
--- a/b2/subex.c
+++ b/b2/subex.c
@@ -135,19 +135,6 @@ static char *compose(const struct chunk *c,
 }
 
 
-struct param *make_var(const char *name, enum relop op, const char *val)
-{
-	struct param *var;
-
-	var = alloc_type(struct param);
-	var->u.name = unique(name);
-	var->op = op;
-	var->value.u.s = unique(val);
-	var->next = NULL;
-	return var;
-}
-
-
 static void do_assign(const char *name, struct param **out, enum relop op,
     const char *val)
 {
@@ -250,26 +237,3 @@ struct param *substitute(const struct subst *sub, const struct param *in)
 	recurse_sub(sub, in, NULL, NULL, NULL, &out);
 	return out;
 }
-
-
-const char *var_lookup(const struct param *vars, const char *name)
-{
-	while (vars) {
-		if (vars->u.name == name)
-			return vars->value.u.s;
-		vars = vars->next;
-	}
-	return NULL;
-}
-
-
-void free_vars(struct param *vars)
-{
-	struct param *next;
-
-	while (vars) {
-		next = vars->next;
-		free(vars);
-		vars = next;
-	}
-}
diff --git a/b2/subex.h b/b2/subex.h
index cd2f090..e280bdc 100644
--- a/b2/subex.h
+++ b/b2/subex.h
@@ -18,8 +18,5 @@
 
 
 struct param *substitute(const struct subst *sub, const struct param *in);
-struct param *make_var(const char *name, enum relop op, const char *val);
-const char *var_lookup(const struct param *vars, const char *name);
-void free_vars(struct param *vars);
 
 #endif /* !SUBEX_H */