diff --git a/builtin-fsck.c b/builtin-fsck.c
index 2d88e4570f..0e5faae381 100644
--- a/builtin-fsck.c
+++ b/builtin-fsck.c
@@ -47,6 +47,7 @@ static void objreport(struct object *obj, const char *severity,
 	fputs("\n", stderr);
 }
 
+__attribute__((format (printf, 2, 3)))
 static int objerror(struct object *obj, const char *err, ...)
 {
 	va_list params;
@@ -57,6 +58,7 @@ static int objerror(struct object *obj, const char *err, ...)
 	return -1;
 }
 
+__attribute__((format (printf, 3, 4)))
 static int fsck_error_func(struct object *obj, int type, const char *err, ...)
 {
 	va_list params;
diff --git a/builtin-update-index.c b/builtin-update-index.c
index 92beaaf4b3..a6b7f2d636 100644
--- a/builtin-update-index.c
+++ b/builtin-update-index.c
@@ -27,6 +27,7 @@ static int mark_valid_only;
 #define MARK_VALID 1
 #define UNMARK_VALID 2
 
+__attribute__((format (printf, 1, 2)))
 static void report(const char *fmt, ...)
 {
 	va_list vp;
diff --git a/builtin-upload-archive.c b/builtin-upload-archive.c
index 29446e84cc..73f788ef24 100644
--- a/builtin-upload-archive.c
+++ b/builtin-upload-archive.c
@@ -67,6 +67,7 @@ static int run_upload_archive(int argc, const char **argv, const char *prefix)
 	return write_archive(sent_argc, sent_argv, prefix, 0);
 }
 
+__attribute__((format (printf, 1, 2)))
 static void error_clnt(const char *fmt, ...)
 {
 	char buf[1024];
diff --git a/cache.h b/cache.h
index f7533ff862..72a311bafa 100644
--- a/cache.h
+++ b/cache.h
@@ -967,7 +967,9 @@ extern void *alloc_object_node(void);
 extern void alloc_report(void);
 
 /* trace.c */
+__attribute__((format (printf, 1, 2)))
 extern void trace_printf(const char *format, ...);
+__attribute__((format (printf, 2, 3)))
 extern void trace_argv_printf(const char **argv, const char *format, ...);
 
 /* convert.c */
diff --git a/color.h b/color.h
index 18abeb7c7d..7d8da6fe22 100644
--- a/color.h
+++ b/color.h
@@ -29,7 +29,9 @@ int git_color_default_config(const char *var, const char *value, void *cb);
 int git_config_colorbool(const char *var, const char *value, int stdout_is_tty);
 void color_parse(const char *value, const char *var, char *dst);
 void color_parse_mem(const char *value, int len, const char *var, char *dst);
+__attribute__((format (printf, 3, 4)))
 int color_fprintf(FILE *fp, const char *color, const char *fmt, ...);
+__attribute__((format (printf, 3, 4)))
 int color_fprintf_ln(FILE *fp, const char *color, const char *fmt, ...);
 int color_fwrite_lines(FILE *fp, const char *color, size_t count, const char *buf);
 
diff --git a/daemon.c b/daemon.c
index ce4800621c..5783e24011 100644
--- a/daemon.c
+++ b/daemon.c
@@ -77,6 +77,7 @@ static void logreport(int priority, const char *err, va_list params)
 	}
 }
 
+__attribute__((format (printf, 1, 2)))
 static void logerror(const char *err, ...)
 {
 	va_list params;
@@ -85,6 +86,7 @@ static void logerror(const char *err, ...)
 	va_end(params);
 }
 
+__attribute__((format (printf, 1, 2)))
 static void loginfo(const char *err, ...)
 {
 	va_list params;
diff --git a/fsck.h b/fsck.h
index 008456b675..1e4f527318 100644
--- a/fsck.h
+++ b/fsck.h
@@ -17,6 +17,7 @@ typedef int (*fsck_walk_func)(struct object *obj, int type, void *data);
 /* callback for fsck_object, type is FSCK_ERROR or FSCK_WARN */
 typedef int (*fsck_error)(struct object *obj, int type, const char *err, ...);
 
+__attribute__((format (printf, 3, 4)))
 int fsck_error_function(struct object *obj, int type, const char *fmt, ...);
 
 /* descend in all linked child objects
diff --git a/imap-send.c b/imap-send.c
index 834301cf40..de8114bac0 100644
--- a/imap-send.c
+++ b/imap-send.c
@@ -104,13 +104,16 @@ static const char imap_send_usage[] = "git imap-send < <mbox>";
 
 static int Verbose, Quiet;
 
+__attribute__((format (printf, 1, 2)))
 static void imap_info(const char *, ...);
+__attribute__((format (printf, 1, 2)))
 static void imap_warn(const char *, ...);
 
 static char *next_arg(char **);
 
 static void free_generic_messages(struct message *);
 
+__attribute__((format (printf, 3, 4)))
 static int nfsnprintf(char *buf, int blen, const char *fmt, ...);
 
 static int nfvasprintf(char **strp, const char *fmt, va_list ap)
@@ -562,6 +565,7 @@ static struct imap_cmd *v_issue_imap_cmd(struct imap_store *ctx,
 	return cmd;
 }
 
+__attribute__((format (printf, 3, 4)))
 static struct imap_cmd *issue_imap_cmd(struct imap_store *ctx,
 				       struct imap_cmd_cb *cb,
 				       const char *fmt, ...)
@@ -575,6 +579,7 @@ static struct imap_cmd *issue_imap_cmd(struct imap_store *ctx,
 	return ret;
 }
 
+__attribute__((format (printf, 3, 4)))
 static int imap_exec(struct imap_store *ctx, struct imap_cmd_cb *cb,
 		     const char *fmt, ...)
 {
@@ -590,6 +595,7 @@ static int imap_exec(struct imap_store *ctx, struct imap_cmd_cb *cb,
 	return get_cmd_result(ctx, cmdp);
 }
 
+__attribute__((format (printf, 3, 4)))
 static int imap_exec_m(struct imap_store *ctx, struct imap_cmd_cb *cb,
 		       const char *fmt, ...)
 {
@@ -880,7 +886,7 @@ static int get_cmd_result(struct imap_store *ctx, struct imap_cmd *tcmd)
 				if (!strcmp("NO", arg)) {
 					if (cmdp->cb.create && cmd && (cmdp->cb.trycreate || !memcmp(cmd, "[TRYCREATE]", 11))) { /* SELECT, APPEND or UID COPY */
 						p = strchr(cmdp->cmd, '"');
-						if (!issue_imap_cmd(ctx, NULL, "CREATE \"%.*s\"", strchr(p + 1, '"') - p + 1, p)) {
+						if (!issue_imap_cmd(ctx, NULL, "CREATE \"%.*s\"", (int)(strchr(p + 1, '"') - p + 1), p)) {
 							resp = RESP_BAD;
 							goto normal;
 						}
diff --git a/merge-recursive.c b/merge-recursive.c
index f55b7ebe11..baabe2c356 100644
--- a/merge-recursive.c
+++ b/merge-recursive.c
@@ -86,6 +86,7 @@ static void flush_output(struct merge_options *o)
 	}
 }
 
+__attribute__((format (printf, 3, 4)))
 static void output(struct merge_options *o, int v, const char *fmt, ...)
 {
 	int len;
@@ -214,7 +215,8 @@ struct tree *write_tree_from_memory(struct merge_options *o)
 		for (i = 0; i < active_nr; i++) {
 			struct cache_entry *ce = active_cache[i];
 			if (ce_stage(ce))
-				output(o, 0, "%d %.*s", ce_stage(ce), ce_namelen(ce), ce->name);
+				output(o, 0, "%d %.*s", ce_stage(ce),
+				       (int)ce_namelen(ce), ce->name);
 		}
 		return NULL;
 	}
diff --git a/strbuf.h b/strbuf.h
index d05e056dd3..fa07ecf094 100644
--- a/strbuf.h
+++ b/strbuf.h
@@ -117,7 +117,7 @@ struct strbuf_expand_dict_entry {
 };
 extern size_t strbuf_expand_dict_cb(struct strbuf *sb, const char *placeholder, void *context);
 
-__attribute__((format(printf,2,3)))
+__attribute__((format (printf,2,3)))
 extern void strbuf_addf(struct strbuf *sb, const char *fmt, ...);
 
 extern size_t strbuf_fread(struct strbuf *, size_t, FILE *);