diff --git a/match.c b/match.c
index eb9b383..05d8a8a 100644
--- a/match.c
+++ b/match.c
@@ -3,6 +3,7 @@
 //
 
 #include <ctype.h>
+#include <stdbool.h>
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
@@ -14,13 +15,13 @@
 
 #ifdef DEBUG_HEAP
 // Doubly-linked list operations:
-#define DLL_PREPEND(head, node) do { (node)->atme = &(head); (node)->next = head; if (head) (head)->atme = &(node)->next; head = node; } while(0)
-#define DLL_REMOVE(node) do { *(node)->atme = (node)->next; if ((node)->next) (node)->next->atme = (node)->atme; } while(0)
+#define DLL_PREPEND(head, node) do { (node)->atme = &(head); (node)->next = head; if (head) (head)->atme = &(node)->next; head = node; } while(false)
+#define DLL_REMOVE(node) do { *(node)->atme = (node)->next; if ((node)->next) (node)->next->atme = (node)->atme; } while(false)
 #endif
 
 // Refcounting ownership-setting macros:
-#define ADD_OWNER(owner, m) do { owner = m; ++(m)->refcount; } while(0)
-#define REMOVE_OWNERSHIP(owner) do { if (owner) { --(owner)->refcount; recycle_if_unused(&(owner)); owner = NULL; } } while(0)
+#define ADD_OWNER(owner, m) do { owner = m; ++(m)->refcount; } while(false)
+#define REMOVE_OWNERSHIP(owner) do { if (owner) { --(owner)->refcount; recycle_if_unused(&(owner)); owner = NULL; } } while(false)
 
 // New match objects are either recycled from unused match objects or allocated
 // from the heap. While it is in use, the match object is stored in the
diff --git a/pattern.c b/pattern.c
index cf5b095..2a054e5 100644
--- a/pattern.c
+++ b/pattern.c
@@ -12,7 +12,7 @@
 #include "pattern.h"
 #include "utils.h"
 
-#define file_err(f, ...) do { fprint_line(stderr, f, __VA_ARGS__); exit(EXIT_FAILURE); } while(0)
+#define file_err(f, ...) do { fprint_line(stderr, f, __VA_ARGS__); exit(EXIT_FAILURE); } while(false)
 
 __attribute__((nonnull))
 static pat_t *expand_chain(file_t *f, pat_t *first);
diff --git a/utils.h b/utils.h
index f3f81f0..4c3a065 100644
--- a/utils.h
+++ b/utils.h
@@ -13,7 +13,7 @@
 #include "match.h"
 
 #define streq(a, b) (strcmp(a, b) == 0)
-#define check(cond, ...) do { if (!(cond)) { (void)fprintf(stderr, __VA_ARGS__); (void)fwrite("\n", 1, 1, stderr); exit(EXIT_FAILURE); } } while(0)
+#define check(cond, ...) do { if (!(cond)) { (void)fprintf(stderr, __VA_ARGS__); (void)fwrite("\n", 1, 1, stderr); exit(EXIT_FAILURE); } } while(false)
 #define new(t) memcheck(calloc(1, sizeof(t)))
 #define xcalloc(a,b) memcheck(calloc(a,b))
 #define xrealloc(a,b) memcheck(realloc(a,b))