diff --git a/library/platform_util.c b/library/platform_util.c
index 8bd53c6..f2f83e6 100644
--- a/library/platform_util.c
+++ b/library/platform_util.c
@@ -21,7 +21,7 @@
  */
 
 /*
- * Ensure gmtime_r is available even with -std=c99; must be included before
+ * Ensure gmtime_r is available even with -std=c99; must be defined before
  * config.h, which pulls in glibc's features.h. Harmless on other platforms.
  */
 #if !defined(_POSIX_C_SOURCE)
diff --git a/library/threading.c b/library/threading.c
index 3abb17c..e7c8d98 100644
--- a/library/threading.c
+++ b/library/threading.c
@@ -20,7 +20,7 @@
  */
 
 /*
- * Ensure gmtime_r is available even with -std=c99; must be included before
+ * Ensure gmtime_r is available even with -std=c99; must be defined before
  * config.h, which pulls in glibc's features.h. Harmless on other platforms.
  */
 #if !defined(_POSIX_C_SOURCE)