diff --git a/.clang-format b/.clang-format
new file mode 100644
index 0000000..27838ac
--- /dev/null
+++ b/.clang-format
@@ -0,0 +1,32 @@
+# clang-format is fairly limited, and these rules are approximate:
+#  - array initializers can get terribly mangled with clang-format 12.0,
+#  - sometimes it still aligns with space characters,
+#  - struct name NL { NL ... NL } NL name; is unachievable.
+BasedOnStyle: GNU
+ColumnLimit: 80
+IndentWidth: 4
+TabWidth: 4
+UseTab: ForContinuationAndIndentation
+BreakBeforeBraces: Allman
+SpaceAfterCStyleCast: true
+AlignAfterOpenBracket: DontAlign
+AlignOperands: DontAlign
+AlignConsecutiveMacros: Consecutive
+AllowAllArgumentsOnNextLine: false
+AllowAllParametersOfDeclarationOnNextLine: false
+IndentGotoLabels: false
+
+# IncludeCategories has some potential, but it may also break the build.
+# Note that the documentation says the value should be "Never".
+SortIncludes: false
+
+# This is a compromise, it generally works out aesthetically better.
+BinPackArguments: false
+
+# Unfortunately, this can't be told to align to column 40 or so.
+SpacesBeforeTrailingComments: 2
+
+# liberty-specific macro body wrappers.
+MacroBlockBegin: "BLOCK_START"
+MacroBlockEnd: "BLOCK_END"
+ForEachMacros: ["LIST_FOR_EACH"]
diff --git a/common.c b/common.c
index 656184e..d9d2a61 100644
--- a/common.c
+++ b/common.c
@@ -22,11 +22,11 @@
 #define LIBERTY_WANT_PROTO_IRC
 
 #ifdef WANT_SYSLOG_LOGGING
-	#define print_fatal_data    ((void *) LOG_ERR)
-	#define print_error_data    ((void *) LOG_ERR)
-	#define print_warning_data  ((void *) LOG_WARNING)
-	#define print_status_data   ((void *) LOG_INFO)
-	#define print_debug_data    ((void *) LOG_DEBUG)
+#define print_fatal_data    ((void *) LOG_ERR)
+#define print_error_data    ((void *) LOG_ERR)
+#define print_warning_data  ((void *) LOG_WARNING)
+#define print_status_data   ((void *) LOG_INFO)
+#define print_debug_data    ((void *) LOG_DEBUG)
 #endif // WANT_SYSLOG_LOGGING
 
 #include "liberty/liberty.c"
@@ -87,15 +87,15 @@ static time_t
 unixtime_msec (long *msec)
 {
 #ifdef _POSIX_TIMERS
-        struct timespec tp;
-        hard_assert (clock_gettime (CLOCK_REALTIME, &tp) != -1);
-        *msec = tp.tv_nsec / 1000000;
+	struct timespec tp;
+	hard_assert (clock_gettime (CLOCK_REALTIME, &tp) != -1);
+	*msec = tp.tv_nsec / 1000000;
 #else // ! _POSIX_TIMERS
-        struct timeval tp;
-        hard_assert (gettimeofday (&tp, NULL) != -1);
-        *msec = tp.tv_usec / 1000;
+	struct timeval tp;
+	hard_assert (gettimeofday (&tp, NULL) != -1);
+	*msec = tp.tv_usec / 1000;
 #endif // ! _POSIX_TIMERS
-        return tp.tv_sec;
+	return tp.tv_sec;
 }
 
 // --- Logging -----------------------------------------------------------------