diff --git a/Machines/AmstradCPC/Keyboard.cpp b/Machines/AmstradCPC/Keyboard.cpp
index 98b67e8ae..7473f942f 100644
--- a/Machines/AmstradCPC/Keyboard.cpp
+++ b/Machines/AmstradCPC/Keyboard.cpp
@@ -151,7 +151,7 @@ const uint16_t *CharacterMapper::sequence_for_character(char character) const {
 #undef SHIFT
 #undef X
 
-	return table_lookup_sequence_for_character(key_sequences, sizeof(key_sequences), character);
+	return table_lookup_sequence_for_character(key_sequences, character);
 }
 
 bool CharacterMapper::needs_pause_after_key(uint16_t key) const {
diff --git a/Machines/Commodore/Vic-20/Keyboard.cpp b/Machines/Commodore/Vic-20/Keyboard.cpp
index 1b79bd414..62493d0e1 100644
--- a/Machines/Commodore/Vic-20/Keyboard.cpp
+++ b/Machines/Commodore/Vic-20/Keyboard.cpp
@@ -151,5 +151,5 @@ const uint16_t *CharacterMapper::sequence_for_character(char character) const {
 #undef SHIFT
 #undef X
 
-	return table_lookup_sequence_for_character(key_sequences, sizeof(key_sequences), character);
+	return table_lookup_sequence_for_character(key_sequences, character);
 }
diff --git a/Machines/Electron/Keyboard.cpp b/Machines/Electron/Keyboard.cpp
index c554c2cbe..689e5707f 100644
--- a/Machines/Electron/Keyboard.cpp
+++ b/Machines/Electron/Keyboard.cpp
@@ -145,7 +145,7 @@ const uint16_t *CharacterMapper::sequence_for_character(char character) const {
 #undef SHIFT
 #undef X
 
-	return table_lookup_sequence_for_character(key_sequences, sizeof(key_sequences), character);
+	return table_lookup_sequence_for_character(key_sequences, character);
 }
 
 bool CharacterMapper::needs_pause_after_key(uint16_t key) const {
diff --git a/Machines/Oric/Keyboard.cpp b/Machines/Oric/Keyboard.cpp
index 2e373ad57..3b12bc7e2 100644
--- a/Machines/Oric/Keyboard.cpp
+++ b/Machines/Oric/Keyboard.cpp
@@ -127,5 +127,5 @@ const uint16_t *CharacterMapper::sequence_for_character(char character) const {
 #undef SHIFT
 #undef X
 
-	return table_lookup_sequence_for_character(key_sequences, sizeof(key_sequences), character);
+	return table_lookup_sequence_for_character(key_sequences, character);
 }
diff --git a/Machines/Sinclair/Keyboard/Keyboard.cpp b/Machines/Sinclair/Keyboard/Keyboard.cpp
index 1e9db2bf8..f0cd23b39 100644
--- a/Machines/Sinclair/Keyboard/Keyboard.cpp
+++ b/Machines/Sinclair/Keyboard/Keyboard.cpp
@@ -275,13 +275,13 @@ const uint16_t *CharacterMapper::sequence_for_character(char character) const {
 
 	switch(machine_) {
 		case Machine::ZX80:
-		return table_lookup_sequence_for_character(zx80_key_sequences, sizeof(zx80_key_sequences), character);
+		return table_lookup_sequence_for_character(zx80_key_sequences, character);
 
 		case Machine::ZX81:
-		return table_lookup_sequence_for_character(zx81_key_sequences, sizeof(zx81_key_sequences), character);
+		return table_lookup_sequence_for_character(zx81_key_sequences, character);
 
 		case Machine::ZXSpectrum:
-		return table_lookup_sequence_for_character(spectrum_key_sequences, sizeof(zx81_key_sequences), character);
+		return table_lookup_sequence_for_character(spectrum_key_sequences, character);
 	}
 }
 
diff --git a/Machines/Utility/Typer.cpp b/Machines/Utility/Typer.cpp
index 9706d85bf..1e290bef5 100644
--- a/Machines/Utility/Typer.cpp
+++ b/Machines/Utility/Typer.cpp
@@ -131,13 +131,3 @@ bool Typer::type_next_character() {
 
 	return true;
 }
-
-// MARK: - Character mapper
-
-const uint16_t *CharacterMapper::table_lookup_sequence_for_character(const KeySequence *sequences, std::size_t length, char character) const {
-	std::size_t ucharacter = size_t((unsigned char)character);
-	if(ucharacter >= (length / sizeof(KeySequence))) return nullptr;
-	if(sequences[ucharacter][0] == MachineTypes::MappedKeyboardMachine::KeyNotMapped) return nullptr;
-	return sequences[ucharacter];
-}
-
diff --git a/Machines/Utility/Typer.hpp b/Machines/Utility/Typer.hpp
index 0e0a15b3a..79ac1b86a 100644
--- a/Machines/Utility/Typer.hpp
+++ b/Machines/Utility/Typer.hpp
@@ -44,11 +44,15 @@ class CharacterMapper {
 		typedef uint16_t KeySequence[16];
 
 		/*!
-			Provided in the base class as a convenience: given the lookup table of key sequences @c sequences,
-			with @c length entries, returns the sequence for character @c character if it exists; otherwise
-			returns @c nullptr.
+			Provided in the base class as a convenience: given the C array of key sequences @c sequences,
+			returns the sequence for character @c character if it exists; otherwise returns @c nullptr.
 		*/
-		const uint16_t *table_lookup_sequence_for_character(const KeySequence *sequences, std::size_t length, char character) const;
+		template <typename Collection> const uint16_t *table_lookup_sequence_for_character(const Collection &sequences, char character) const {
+			std::size_t ucharacter = size_t((unsigned char)character);
+			if(ucharacter >= sizeof(sequences) / sizeof(KeySequence)) return nullptr;
+			if(sequences[ucharacter][0] == MachineTypes::MappedKeyboardMachine::KeyNotMapped) return nullptr;
+			return sequences[ucharacter];
+		}
 };
 
 /*!