Add a cast to a malloc to shut up the DEC Unix compiler.
diff --git a/Modules/regexpr.c b/Modules/regexpr.c
index 115f327..90bff87 100644
--- a/Modules/regexpr.c
+++ b/Modules/regexpr.c
@@ -177,7 +177,7 @@
 { \
    if (stack.current->next == NULL) \
    { \
-      stack.current->next = malloc(sizeof(item_page_t)); \
+      stack.current->next = (item_page_t *)malloc(sizeof(item_page_t)); \
       if (stack.current->next == NULL) \
          on_error; \
       stack.current->next->prev = stack.current; \