diff --git a/src/3rdparty/squirrel/squirrel/sqstate.cpp b/src/3rdparty/squirrel/squirrel/sqstate.cpp
index 09341d84dd..42df3c5e71 100644
--- a/src/3rdparty/squirrel/squirrel/sqstate.cpp
+++ b/src/3rdparty/squirrel/squirrel/sqstate.cpp
@@ -538,7 +538,7 @@ void SQStringTable::AllocNodes(SQInteger size)
 {
 	_numofslots = size;
 	_strings = (SQString**)SQ_MALLOC(sizeof(SQString*)*_numofslots);
-	memset(_strings,0,sizeof(SQString*)*(size_t)_numofslots);
+	std::fill_n(_strings, _numofslots, nullptr);
 }
 
 static const std::hash<std::string_view> string_table_hash{};
diff --git a/src/blitter/8bpp_base.cpp b/src/blitter/8bpp_base.cpp
index a936138a1a..fceb5c4adf 100644
--- a/src/blitter/8bpp_base.cpp
+++ b/src/blitter/8bpp_base.cpp
@@ -43,9 +43,10 @@ void Blitter_8bppBase::DrawLine(void *video, int x, int y, int x2, int y2, int s
 
 void Blitter_8bppBase::DrawRect(void *video, int width, int height, uint8_t colour)
 {
+	std::byte *p = static_cast<std::byte *>(video);
 	do {
-		memset(video, colour, width);
-		video = (uint8_t *)video + _screen.pitch;
+		std::fill_n(p, width, static_cast<std::byte>(colour));
+		p += _screen.pitch;
 	} while (--height);
 }
 
diff --git a/src/mixer.cpp b/src/mixer.cpp
index 81205cf398..0e92cd5333 100644
--- a/src/mixer.cpp
+++ b/src/mixer.cpp
@@ -131,7 +131,7 @@ void MxMixSamples(void *buffer, uint samples)
 	}
 
 	/* Clear the buffer */
-	memset(buffer, 0, sizeof(int16_t) * 2 * samples);
+	std::fill_n(static_cast<int16_t *>(buffer), 2 * samples, 0);
 
 	{
 		std::lock_guard<std::mutex> lock{ _music_stream_mutex };
diff --git a/src/settings.cpp b/src/settings.cpp
index 41e6b026da..1522cac8eb 100644
--- a/src/settings.cpp
+++ b/src/settings.cpp
@@ -281,15 +281,15 @@ static std::optional<std::vector<uint32_t>> ParseIntList(std::string_view str)
 static bool LoadIntList(std::optional<std::string_view> str, void *array, int nelems, VarType type)
 {
 	size_t elem_size = SlVarSize(type);
+	std::byte *p = static_cast<std::byte *>(array);
 	if (!str.has_value()) {
-		memset(array, 0, nelems * elem_size);
+		std::fill_n(p, nelems * elem_size, static_cast<std::byte>(0));
 		return true;
 	}
 
 	auto opt_items = ParseIntList(*str);
 	if (!opt_items.has_value() || opt_items->size() != (size_t)nelems) return false;
 
-	std::byte *p = static_cast<std::byte *>(array);
 	for (auto item : *opt_items) {
 		WriteValue(p, type, item);
 		p += elem_size;
diff --git a/src/spritecache.cpp b/src/spritecache.cpp
index 50f274b2ce..e196ad202b 100644
--- a/src/spritecache.cpp
+++ b/src/spritecache.cpp
@@ -448,7 +448,7 @@ static void *ReadRecolourSprite(SpriteFile &file, size_t file_pos, uint num, Spr
 		uint8_t *dest_tmp = new uint8_t[std::max(RECOLOUR_SPRITE_SIZE, num)];
 
 		/* Only a few recolour sprites are less than 257 bytes */
-		if (num < RECOLOUR_SPRITE_SIZE) memset(dest_tmp, 0, RECOLOUR_SPRITE_SIZE);
+		if (num < RECOLOUR_SPRITE_SIZE) std::fill_n(dest_tmp, RECOLOUR_SPRITE_SIZE, 0);
 		file.ReadBlock(dest_tmp, num);
 
 		/* The data of index 0 is never used; "literal 00" according to the (New)GRF specs. */
diff --git a/src/video/allegro_v.cpp b/src/video/allegro_v.cpp
index faf4091151..424fafa2a9 100644
--- a/src/video/allegro_v.cpp
+++ b/src/video/allegro_v.cpp
@@ -203,7 +203,7 @@ static bool CreateMainSurface(uint w, uint h)
 	_screen.dst_ptr = _allegro_screen->line[0];
 
 	/* Initialise the screen so we don't blit garbage to the screen */
-	memset(_screen.dst_ptr, 0, static_cast<size_t>(_screen.height) * _screen.pitch);
+	std::fill_n(static_cast<std::byte *>(_screen.dst_ptr), static_cast<size_t>(_screen.height) * _screen.pitch, static_cast<std::byte>(0));
 
 	/* Set the mouse at the place where we expect it */
 	poll_mouse();