diff --git a/src/constants.h b/src/constants.h
index bde43b5..f195cc6 100644
--- a/src/constants.h
+++ b/src/constants.h
@@ -21,13 +21,13 @@
 #define CONSTANTS_H 1
 
 /* Names of used environment variables. */
-#define ENV_NAME_FDS "COLORED_STDERR_FDS"
-#define ENV_NAME_PRE_STRING "COLORED_STDERR_PRE"
+#define ENV_NAME_FDS         "COLORED_STDERR_FDS"
+#define ENV_NAME_PRE_STRING  "COLORED_STDERR_PRE"
 #define ENV_NAME_POST_STRING "COLORED_STDERR_POST"
 #define ENV_NAME_FORCE_WRITE "COLORED_STDERR_FORCE_WRITE"
 
 /* Strings written before/after each matched function. */
-#define DEFAULT_PRE_STRING "\033[91m"
+#define DEFAULT_PRE_STRING  "\033[91m"
 #define DEFAULT_POST_STRING "\033[0m"
 
 /* Number of elements to allocate statically. Highest descriptor observed in