diff --git a/builtin/checkout.c b/builtin/checkout.c
index 5e5afa0f267..a636e71e05c 100644
--- a/builtin/checkout.c
+++ b/builtin/checkout.c
@@ -223,7 +223,7 @@ static int check_stages(unsigned stages, const struct cache_entry *ce, int pos)
 		ce = the_repository->index->cache[pos];
 		if (strcmp(name, ce->name))
 			break;
-		seen |= (1 << ce_stage(ce));
+		seen |= (1U << ce_stage(ce));
 		pos++;
 	}
 	if ((stages & seen) != stages)
diff --git a/builtin/merge-tree.c b/builtin/merge-tree.c
index c5ed472967a..d0104dfa0c7 100644
--- a/builtin/merge-tree.c
+++ b/builtin/merge-tree.c
@@ -270,13 +270,13 @@ static void unresolved(const struct traverse_info *info, struct name_entry n[3])
 	unsigned dirmask = 0, mask = 0;
 
 	for (i = 0; i < 3; i++) {
-		mask |= (1 << i);
+		mask |= (1U << i);
 		/*
 		 * Treat missing entries as directories so that we return
 		 * after unresolved_directory has handled this.
 		 */
 		if (!n[i].mode || S_ISDIR(n[i].mode))
-			dirmask |= (1 << i);
+			dirmask |= (1U << i);
 	}
 
 	unresolved_directory(info, n);
diff --git a/builtin/receive-pack.c b/builtin/receive-pack.c
index 9d2c07f68da..b958eeee8fe 100644
--- a/builtin/receive-pack.c
+++ b/builtin/receive-pack.c
@@ -1306,7 +1306,7 @@ static int update_shallow_ref(struct command *cmd, struct shallow_info *si)
 	struct shallow_lock shallow_lock = SHALLOW_LOCK_INIT;
 	struct oid_array extra = OID_ARRAY_INIT;
 	struct check_connected_options opt = CHECK_CONNECTED_INIT;
-	uint32_t mask = 1 << (cmd->index % 32);
+	uint32_t mask = 1U << (cmd->index % 32);
 	int i;
 
 	trace_printf_key(&trace_shallow,
diff --git a/color.c b/color.c
index 227a5ab2f42..ab9a3d2a097 100644
--- a/color.c
+++ b/color.c
@@ -317,7 +317,7 @@ int color_parse_mem(const char *value, int value_len, char *dst)
 		}
 		val = parse_attr(word, wordlen);
 		if (0 <= val)
-			attr |= (1 << val);
+			attr |= (1U << val);
 		else
 			goto bad;
 	}
@@ -340,7 +340,7 @@ int color_parse_mem(const char *value, int value_len, char *dst)
 			sep++;
 
 		for (i = 0; attr; i++) {
-			unsigned bit = (1 << i);
+			unsigned bit = (1U << i);
 			if (!(attr & bit))
 				continue;
 			attr &= ~bit;
diff --git a/delta-islands.c b/delta-islands.c
index 84435512593..a041cfa1ab3 100644
--- a/delta-islands.c
+++ b/delta-islands.c
@@ -78,7 +78,7 @@ static int island_bitmap_is_subset(struct island_bitmap *self,
 }
 
 #define ISLAND_BITMAP_BLOCK(x) (x / 32)
-#define ISLAND_BITMAP_MASK(x) (1 << (x % 32))
+#define ISLAND_BITMAP_MASK(x) (1U << (x % 32))
 
 static void island_bitmap_set(struct island_bitmap *self, uint32_t i)
 {
diff --git a/diff-delta.c b/diff-delta.c
index 77fea08dfb0..fbdfec7037f 100644
--- a/diff-delta.c
+++ b/diff-delta.c
@@ -156,7 +156,7 @@ struct delta_index * create_delta_index(const void *buf, unsigned long bufsize)
 	}
 	hsize = entries / 4;
 	for (i = 4; (1u << i) < hsize; i++);
-	hsize = 1 << i;
+	hsize = 1u << i;
 	hmask = hsize - 1;
 
 	/* allocate lookup index */
diff --git a/diff.c b/diff.c
index 266ddf18e73..021df059e0b 100644
--- a/diff.c
+++ b/diff.c
@@ -4815,7 +4815,7 @@ static void prepare_filter_bits(void)
 
 	if (!filter_bit[DIFF_STATUS_ADDED]) {
 		for (i = 0; diff_status_letters[i]; i++)
-			filter_bit[(int) diff_status_letters[i]] = (1 << i);
+			filter_bit[(int) diff_status_letters[i]] = (1U << i);
 	}
 }
 
diff --git a/help.c b/help.c
index 8a830ba35c6..839596156fe 100644
--- a/help.c
+++ b/help.c
@@ -394,7 +394,7 @@ void list_cmds_by_category(struct string_list *list,
 
 	for (i = 0; category_names[i]; i++) {
 		if (!strcmp(cat, category_names[i])) {
-			cat_id = 1UL << i;
+			cat_id = 1U << i;
 			break;
 		}
 	}
diff --git a/imap-send.c b/imap-send.c
index 25c68fd90d7..fdb9e658e70 100644
--- a/imap-send.c
+++ b/imap-send.c
@@ -644,7 +644,7 @@ static void parse_capability(struct imap *imap, char *cmd)
 	while ((arg = next_arg(&cmd)))
 		for (i = 0; i < ARRAY_SIZE(cap_list); i++)
 			if (!strcmp(cap_list[i], arg))
-				imap->caps |= 1 << i;
+				imap->caps |= 1U << i;
 	imap->rcaps = imap->caps;
 }
 
diff --git a/merge-ort.c b/merge-ort.c
index 11029c10be3..5a99bec7a04 100644
--- a/merge-ort.c
+++ b/merge-ort.c
@@ -1218,7 +1218,7 @@ static void collect_rename_info(struct merge_options *opt,
 		return;
 
 	for (side = MERGE_SIDE1; side <= MERGE_SIDE2; ++side) {
-		unsigned side_mask = (1 << side);
+		unsigned side_mask = (1U << side);
 
 		/* Check for deletion on side */
 		if ((filemask & 1) && !(filemask & side_mask))
@@ -2026,7 +2026,7 @@ static void initialize_attr_index(struct merge_options *opt)
 
 		ASSIGN_AND_VERIFY_CI(ci, mi);
 		for (stage = 0; stage < 3; stage++) {
-			unsigned stage_mask = (1 << stage);
+			unsigned stage_mask = (1U << stage);
 
 			if (!(ci->filemask & stage_mask))
 				continue;
@@ -2362,7 +2362,7 @@ static char *handle_path_level_conflicts(struct merge_options *opt,
 	 */
 	if (c_info->reported_already) {
 		clean = 0;
-	} else if (path_in_way(&opt->priv->paths, new_path, 1 << side_index)) {
+	} else if (path_in_way(&opt->priv->paths, new_path, 1U << side_index)) {
 		c_info->reported_already = 1;
 		strbuf_add_separated_string_list(&collision_paths, ", ",
 						 &c_info->source_files);
@@ -2747,7 +2747,7 @@ static void apply_directory_rename_modifications(struct merge_options *opt,
 		ci->filemask = 0;
 		ci->merged.clean = 1;
 		for (i = MERGE_BASE; i <= MERGE_SIDE2; i++) {
-			if (ci->dirmask & (1 << i))
+			if (ci->dirmask & (1U << i))
 				continue;
 			/* zero out any entries related to files */
 			ci->stages[i].mode = 0;
@@ -2915,7 +2915,7 @@ static int process_renames(struct merge_options *opt,
 				assert(side1 == side2);
 				memcpy(&side1->stages[0], &base->stages[0],
 				       sizeof(merged));
-				side1->filemask |= (1 << MERGE_BASE);
+				side1->filemask |= (1U << MERGE_BASE);
 				/* Mark base as resolved by removal */
 				base->merged.is_null = 1;
 				base->merged.clean = 1;
@@ -3002,7 +3002,7 @@ static int process_renames(struct merge_options *opt,
 		target_index = pair->score; /* from collect_renames() */
 		assert(target_index == 1 || target_index == 2);
 		other_source_index = 3 - target_index;
-		old_sidemask = (1 << other_source_index); /* 2 or 4 */
+		old_sidemask = (1U << other_source_index); /* 2 or 4 */
 		source_deleted = (oldinfo->filemask == 1);
 		collision = ((newinfo->filemask & old_sidemask) != 0);
 		type_changed = !source_deleted &&
@@ -3116,7 +3116,7 @@ static int process_renames(struct merge_options *opt,
 			 */
 			memcpy(&newinfo->stages[0], &oldinfo->stages[0],
 			       sizeof(newinfo->stages[0]));
-			newinfo->filemask |= (1 << MERGE_BASE);
+			newinfo->filemask |= (1U << MERGE_BASE);
 			newinfo->pathnames[0] = oldpath;
 			if (type_changed) {
 				/* rename vs. typechange */
@@ -3139,7 +3139,7 @@ static int process_renames(struct merge_options *opt,
 				memcpy(&newinfo->stages[other_source_index],
 				       &oldinfo->stages[other_source_index],
 				       sizeof(newinfo->stages[0]));
-				newinfo->filemask |= (1 << other_source_index);
+				newinfo->filemask |= (1U << other_source_index);
 				newinfo->pathnames[other_source_index] = oldpath;
 			}
 		}
@@ -3990,7 +3990,7 @@ static int process_entry(struct merge_options *opt,
 		ci->match_mask = (ci->match_mask & ~ci->dirmask);
 		ci->dirmask = 0;
 		for (i = MERGE_BASE; i <= MERGE_SIDE2; i++) {
-			if (ci->filemask & (1 << i))
+			if (ci->filemask & (1U << i))
 				continue;
 			ci->stages[i].mode = 0;
 			oidcpy(&ci->stages[i].oid, null_oid());
diff --git a/xdiff/xhistogram.c b/xdiff/xhistogram.c
index 16a8fe2f3f3..18a037a3ba8 100644
--- a/xdiff/xhistogram.c
+++ b/xdiff/xhistogram.c
@@ -265,7 +265,7 @@ static int find_lcs(xpparam_t const *xpp, xdfenv_t *env,
 	index.rcha.head = NULL;
 
 	index.table_bits = xdl_hashbits(count1);
-	index.records_size = 1 << index.table_bits;
+	index.records_size = 1U << index.table_bits;
 	if (!XDL_CALLOC_ARRAY(index.records, index.records_size))
 		goto cleanup;
 
diff --git a/xdiff/xprepare.c b/xdiff/xprepare.c
index c84549f6c50..18c176462ec 100644
--- a/xdiff/xprepare.c
+++ b/xdiff/xprepare.c
@@ -72,7 +72,7 @@ static int xdl_init_classifier(xdlclassifier_t *cf, long size, long flags) {
 	cf->flags = flags;
 
 	cf->hbits = xdl_hashbits((unsigned int) size);
-	cf->hsize = 1 << cf->hbits;
+	cf->hsize = 1U << cf->hbits;
 
 	if (xdl_cha_init(&cf->ncha, sizeof(xdlclass_t), size / 4 + 1) < 0) {
 
@@ -174,7 +174,7 @@ static int xdl_prepare_ctx(unsigned int pass, mmfile_t *mf, long narec, xpparam_
 		goto abort;
 
 	hbits = xdl_hashbits((unsigned int) narec);
-	hsize = 1 << hbits;
+	hsize = 1U << hbits;
 	if (!XDL_CALLOC_ARRAY(rhash, hsize))
 		goto abort;
 
