diff --git a/releasenotes.md b/releasenotes.md
index 36405d6f2..0afefc650 100644
--- a/releasenotes.md
+++ b/releasenotes.md
@@ -18,6 +18,7 @@
 - Add printf format to `$assert` and `$error` #2183.
 - Make accepting arguments for `main` a bit more liberal, accepting `main(int argc, ZString* argv)`
 - Make `$echo` and `@sprintf` correctly stringify compile time initializers and slices.
+- Add `--sources` build option to add additional files to compile. #2097
 
 ### Fixes
 - `-2147483648`, MIN literals work correctly.
diff --git a/src/build/build_internal.h b/src/build/build_internal.h
index e17cf3261..55f9fdab8 100644
--- a/src/build/build_internal.h
+++ b/src/build/build_internal.h
@@ -151,5 +151,10 @@ int get_valid_enum_from_string(const char *str, const char *target, const char *
 void check_json_keys(const char *valid_keys[][2], size_t key_count, const char *deprecated_keys[], size_t deprecated_key_count, JSONObject *json, const char *target_name, const char *option);
 long get_valid_integer(BuildParseContext context, JSONObject *table, const char *key, bool mandatory);
 
+INLINE void append_strings_to_strings(const char*** list_of_strings_ptr, const char **strings_to_append)
+{
+	FOREACH(const char *, string, strings_to_append) vec_add(*list_of_strings_ptr, string);
+}
+
 #define APPEND_STRING_LIST(list__, string__) \
 get_list_append_strings(context, json, list__, string__, string__ "-override")
diff --git a/src/build/build_options.c b/src/build/build_options.c
index 65c80fd37..bed916798 100644
--- a/src/build/build_options.c
+++ b/src/build/build_options.c
@@ -43,6 +43,7 @@ const char *arch_os_target[ARCH_OS_TARGET_LAST + 1];
 #define EOUTPUT(string, ...) fprintf(stderr, string "\n", ##__VA_ARGS__) // NOLINT
 #define PRINTF(string, ...) fprintf(stdout, string "\n", ##__VA_ARGS__) // NOLINT
 #define FAIL_WITH_ERR(string, ...) do { fprintf(stderr, "Error: " string "\n\n", ##__VA_ARGS__); usage(false); exit_compiler(EXIT_FAILURE); } while (0) /* NOLINT */
+#define FAIL_WITH_ERR_LONG(string, ...) do { fprintf(stderr, "Error: " string "\n\n", ##__VA_ARGS__); usage(true); exit_compiler(EXIT_FAILURE); } while (0) /* NOLINT */
 #define PROJECT_FAIL_WITH_ERR(string, ...) do { fprintf(stderr, "Error: " string "\n\n", ##__VA_ARGS__); project_usage(); exit_compiler(EXIT_FAILURE); } while (0) /* NOLINT */
 
 static void usage(bool full)
@@ -96,6 +97,7 @@ static void usage(bool full)
 	print_opt("--run-dir <dir>", "Set the directory from where to run the binary (only for run and compile-run).");
 	print_opt("--libdir <dir>", "Add this directory to the c3l library search paths.");
 	print_opt("--lib <name>", "Add this c3l library to the compilation.");
+	print_opt("--sources <file1> [<file2> ...]", "Add these additional sources to the compilation.");
 	if (full)
 	{
 		print_opt("--validation=<option>", "Strictness of code validation: lenient (default), strict, obnoxious (very strict)");
@@ -721,6 +723,20 @@ static void parse_option(BuildOptions *options)
 				options->ansi = parse_opt_select(Ansi, argopt, on_off);
 				return;
 			}
+			if (match_longopt("sources"))
+			{
+				if (at_end() || next_is_opt())
+				{
+					FAIL_WITH_ERR_LONG("'--sources' expected at least one source file.");
+				}
+				do
+				{
+					next_arg();
+					append_file(options);
+
+				} while(!(at_end() || next_is_opt()));
+				return;
+			}
 			if (match_longopt("use-old-slice-copy"))
 			{
 				options->old_slice_copy = true;
@@ -728,7 +744,7 @@ static void parse_option(BuildOptions *options)
 			}
 			if (match_longopt("test-filter"))
 			{
-				if (at_end() || next_is_opt()) error_exit("error: --test-filter needs an argument.");
+				if (at_end() || next_is_opt()) FAIL_WITH_ERR_LONG("error: --test-filter needs an argument.");
 				options->test_filter = next_arg();
 				return;
 			}
@@ -770,13 +786,13 @@ static void parse_option(BuildOptions *options)
 			}
 			if (match_longopt("symtab"))
 			{
-				if (at_end() || next_is_opt()) error_exit("error: --symtab needs a valid integer.");
+				if (at_end() || next_is_opt()) FAIL_WITH_ERR_LONG("error: --symtab needs a valid integer.");
 				const char *symtab_string = next_arg();
 				int symtab = atoi(symtab_string);
-				if (symtab < 1024) error_exit("Expected the --symtab size to be valid positive integer >= 1024.");
+				if (symtab < 1024) FAIL_WITH_ERR_LONG("Expected the --symtab size to be valid positive integer >= 1024.");
 				if (symtab > MAX_SYMTAB_SIZE)
 				{
-					error_exit("The symtab size is too large. The maximum size is %d.", (int)MAX_SYMTAB_SIZE);
+					FAIL_WITH_ERR_LONG("The symtab size is too large. The maximum size is %d.", (int)MAX_SYMTAB_SIZE);
 				}
 				options->symtab_size = next_highest_power_of_2(symtab);
 				return;
diff --git a/src/build/builder.c b/src/build/builder.c
index 5d3f0018d..06d70fc5f 100644
--- a/src/build/builder.c
+++ b/src/build/builder.c
@@ -523,6 +523,11 @@ static void update_build_target_from_options(BuildTarget *target, BuildOptions *
 		target->header_file_dir = target->output_dir ? target->output_dir : target->build_dir;
 	}
 
+	if (options->files)
+	{
+		append_strings_to_strings(&target->source_dirs, options->files);
+	}
+
 	switch (options->compile_option)
 	{
 		case COMPILE_NORMAL:
diff --git a/src/build/common_build.c b/src/build/common_build.c
index c78ba2ac0..f4211726c 100644
--- a/src/build/common_build.c
+++ b/src/build/common_build.c
@@ -113,12 +113,6 @@ const char *get_cflags(BuildParseContext context, JSONObject *json, const char *
 	return cflags ? cflags : original_flags;
 }
 
-INLINE void append_strings_to_strings(const char*** list_of_strings_ptr, const char **strings_to_append)
-{
-	FOREACH(const char *, string, strings_to_append) vec_add(*list_of_strings_ptr, string);
-}
-
-
 void get_list_append_strings(BuildParseContext context, JSONObject *json, const char ***list_ptr, const char *base, const char *override)
 {
 	const char **value = get_optional_string_array(context, json, context.target ? override : base);