diff --git a/releasenotes.md b/releasenotes.md
index da947c593..f76c17040 100644
--- a/releasenotes.md
+++ b/releasenotes.md
@@ -20,6 +20,8 @@
 - Array comparison now uses built-in memcmp on LLVM to enable optimizations.
 - Prevent implicit array casts to pointers with higher alignment #1237.
 - Macro `$case` statements now pick the first match and does not evaluate the rest.
+- `mainfest.json` is now checked for incorrect keys.
+- Added `--list-manifest-properties` to list the available properties in `manifest.json`.
 
 ### Fixes
 - Error with unsigned compare in `@ensure` when early returning 0 #1207.
diff --git a/resources/testproject/lib/clib.c3l/manifest.json b/resources/testproject/lib/clib.c3l/manifest.json
index afaf59e3e..16eff63ac 100644
--- a/resources/testproject/lib/clib.c3l/manifest.json
+++ b/resources/testproject/lib/clib.c3l/manifest.json
@@ -6,7 +6,7 @@
     },
     "macos-aarch64" : {},
     "linux-x64" : {
-      "c-flags-override": "-fPIE"
+      "cflags-override": "-fPIE"
     },
 	"windows-x64" : { }
   }
diff --git a/resources/testproject/lib/clib2.c3l b/resources/testproject/lib/clib2.c3l
index 0e64c8eba..ec52baeab 100644
Binary files a/resources/testproject/lib/clib2.c3l and b/resources/testproject/lib/clib2.c3l differ
diff --git a/src/build/build.h b/src/build/build.h
index a5f1b8765..4b67a77f0 100644
--- a/src/build/build.h
+++ b/src/build/build.h
@@ -400,6 +400,7 @@ typedef struct BuildOptions_
 	bool print_operators;
 	bool print_type_properties;
 	bool print_project_properties;
+	bool print_manifest_properties;
 	bool print_precedence;
 	bool print_build_settings;
 	bool print_linking;
diff --git a/src/build/build_internal.h b/src/build/build_internal.h
index 7e142bd70..482a15e1b 100644
--- a/src/build/build_internal.h
+++ b/src/build/build_internal.h
@@ -99,3 +99,4 @@ const char *get_cflags(const char *file, const char *target, JSONObject *json, c
 void get_list_append_strings(const char *file, const char *target, JSONObject *json, const char ***list_ptr,
                              const char *base, const char *override, const char *add);
 int get_valid_string_setting(const char *file, const char *target, JSONObject *json, const char *key, const char** values, int first_result, int count, const char *expected);
+void check_json_keys(const char* valid_keys[][2], size_t key_count, JSONObject *json, const char *target_name, const char *option);
diff --git a/src/build/build_options.c b/src/build/build_options.c
index f51735b37..1d7308251 100644
--- a/src/build/build_options.c
+++ b/src/build/build_options.c
@@ -165,6 +165,7 @@ static void usage(void)
 	PRINTF("  --list-operators           - List all operators.");
 	PRINTF("  --list-precedence          - List operator precedence order.");
 	PRINTF("  --list-project-properties  - List all available keys used in project.json files.");
+	PRINTF("  --list-manifest-properties  - List all available keys used in manifest.json files.");
 	PRINTF("  --list-targets             - List all architectures the compiler supports.");
 	PRINTF("  --list-type-properties     - List all type properties.");
 	PRINTF("");
@@ -819,6 +820,12 @@ static void parse_option(BuildOptions *options)
 				options->command = COMMAND_PRINT_SYNTAX;
 				return;
 			}
+			if (match_longopt("list-manifest-properties"))
+			{
+				options->print_manifest_properties = true;
+				options->command = COMMAND_PRINT_SYNTAX;
+				return;
+			}
 			if (match_longopt("list-operators"))
 			{
 				options->print_operators = true;
diff --git a/src/build/common_build.c b/src/build/common_build.c
index aac546a7e..4384b94d8 100644
--- a/src/build/common_build.c
+++ b/src/build/common_build.c
@@ -1,6 +1,28 @@
 #include "build_internal.h"
 #include "utils/common.h"
 
+void check_json_keys(const char* valid_keys[][2], size_t key_count, JSONObject *json, const char *target_name, const char *option)
+{
+	static bool failed_shown = false;
+	bool failed = false;
+	for (size_t i = 0; i < json->member_len; i++)
+	{
+		const char *key = json->keys[i];
+		for (size_t j = 0; j < key_count; j++)
+		{
+			if (strcmp(key, valid_keys[j][0]) == 0) goto OK;
+		}
+		eprintf("WARNING: Unknown parameter '%s' in '%s'.\n", key, target_name);
+		failed = true;
+		OK:;
+	}
+	if (failed && !failed_shown)
+	{
+		eprintf("You can use '%s' to list all valid properties.\n", option);
+		failed_shown = true;
+	}
+}
+
 const char *get_optional_string(const char *file, const char *category, JSONObject *table, const char *key)
 {
 	JSONObject *value = json_obj_get(table, key);
diff --git a/src/build/libraries.c b/src/build/libraries.c
index cdf638bb1..876f7fc69 100644
--- a/src/build/libraries.c
+++ b/src/build/libraries.c
@@ -3,6 +3,32 @@
 
 #define MANIFEST_FILE "manifest.json"
 
+const char *manifest_default_keys[][2] = {
+		{"c-sources", "Set the C sources to be compiled."},
+		{"cc", "Set C compiler (defaults to 'cc')."},
+		{"cflags", "C compiler flags."},
+		{"depends", "List of C3 libraries to also include."},
+		{"exec", "Scripts run for all platforms."},
+		{"provides", "The library name"},
+		{"targets", "The map of supported platforms"}
+};
+
+const int manifest_default_keys_count = ELEMENTLEN(manifest_default_keys);
+
+const char *manifest_target_keys[][2] = {
+		{"c-sources-add", "Additional C sources to be compiled for the target."},
+		{"c-sources-override", "C sources to be compiled, overriding global settings."},
+		{"cc", "Set C compiler (defaults to 'cc')."},
+		{"cflags-add", "Additional C compiler flags for the target."},
+		{"cflags-override", "C compiler flags for the target, overriding global settings."},
+		{"depends", "List of C3 libraries to also include for this target."},
+		{"exec", "Scripts to also run for the target."},
+		{"linked-libraries", "Libraries linked by the linker for this target, overriding global settings."},
+		{"link-args", "Linker arguments for this target."},
+};
+
+const int manifest_target_keys_count = ELEMENTLEN(manifest_target_keys);
+
 static inline void parse_library_target(Library *library, LibraryTarget *target, const char *target_name,
                                         JSONObject *object);
 
@@ -15,6 +41,7 @@ static inline void parse_library_type(Library *library, LibraryTarget ***target_
 		JSONObject *member = object->members[i];
 		const char *key = object->keys[i];
 		if (member->type != J_OBJECT) error_exit("Expected a list of properties for a target in %s.", library->dir);
+		check_json_keys(manifest_target_keys, manifest_target_keys_count, member, key, "--list-library-properties");
 		LibraryTarget *library_target = CALLOCS(LibraryTarget);
 		library_target->parent = library;
 		ArchOsTarget target = arch_os_target_from_string(key);
@@ -31,10 +58,10 @@ static inline void parse_library_type(Library *library, LibraryTarget ***target_
 static inline void parse_library_target(Library *library, LibraryTarget *target, const char *target_name,
                                         JSONObject *object)
 {
-	target->link_flags = get_string_array(library->dir, target_name, object, "linkflags", false);
-	target->linked_libs = get_string_array(library->dir, target_name, object, "linked-libs", false);
+	target->link_flags = get_string_array(library->dir, target_name, object, "link-args", false);
+	target->linked_libs = get_string_array(library->dir, target_name, object, "linked-libraries", false);
 	target->depends = get_string_array(library->dir, target_name, object, "depends", false);
-	target->execs = get_string_array(library->dir, target_name, object, "execs", false);
+	target->execs = get_string_array(library->dir, target_name, object, "exec", false);
 	target->cc = get_string(library->dir, target_name, object, "cc", library->cc);
 	target->cflags = get_cflags(library->dir, target_name, object, library->cflags);
 	target->csource_dirs = library->csource_dirs;
@@ -43,6 +70,7 @@ static inline void parse_library_target(Library *library, LibraryTarget *target,
 
 static Library *add_library(JSONObject *object, const char *dir)
 {
+	check_json_keys(manifest_default_keys, manifest_default_keys_count, object, "library", "--list-library-properties");
 	Library *library = CALLOCS(Library);
 	library->dir = dir;
 	const char *provides = get_mandatory_string(dir, NULL, object, "provides");
@@ -54,7 +82,7 @@ static Library *add_library(JSONObject *object, const char *dir)
 		error_exit("Invalid 'provides' module name in %s, was '%s'.", library->dir, res);
 	}
 	library->provides = provides;
-	library->execs = get_optional_string_array(library->dir, NULL, object, "execs");
+	library->execs = get_optional_string_array(library->dir, NULL, object, "exec");
 	library->depends = get_optional_string_array(library->dir, NULL, object, "depends");
 	library->cc = get_optional_string(dir, NULL, object, "cc");
 	library->cflags = get_cflags(library->dir, NULL, object, NULL);
diff --git a/src/build/project.c b/src/build/project.c
index cca127336..186df521f 100644
--- a/src/build/project.c
+++ b/src/build/project.c
@@ -144,37 +144,16 @@ long get_valid_integer(JSONObject *table, const char *key, const char *category,
 	return (long)trunc(value->f);
 }
 
-static void check_json_keys(const char* valid_keys[][2], size_t key_count, JSONObject *json, const char *target_name)
-{
-	static bool failed_shown = false;
-	bool failed = false;
-	for (size_t i = 0; i < json->member_len; i++)
-	{
-		const char *key = json->keys[i];
-		for (size_t j = 0; j < key_count; j++)
-		{
-			if (strcmp(key, valid_keys[j][0]) == 0) goto OK;
-		}
-		eprintf("WARNING: Unknown parameter '%s' in '%s'.\n", key, target_name ? target_name : "default_target");
-		failed = true;
-	OK:;
-	}
-	if (failed && !failed_shown)
-	{
-		eprintf("You can use '--list-project-properties' to list all valid properties.\n");
-		failed_shown = true;
-	}
-}
 
 static void load_into_build_target(JSONObject *json, const char *target_name, BuildTarget *target)
 {
 	if (target_name)
 	{
-		check_json_keys(project_target_keys, project_target_keys_count, json, target_name);
+		check_json_keys(project_target_keys, project_target_keys_count, json, target_name, "--list-project-properties");
 	}
 	else
 	{
-		check_json_keys(project_default_keys, project_default_keys_count, json, NULL);
+		check_json_keys(project_default_keys, project_default_keys_count, json, "default target", "--list-project-properties");
 	}
 	target->cc = get_string(PROJECT_JSON, target_name, json, "cc", target->cc);
 
diff --git a/src/compiler/compiler.c b/src/compiler/compiler.c
index 73df7246b..1063ceb1e 100644
--- a/src/compiler/compiler.c
+++ b/src/compiler/compiler.c
@@ -898,6 +898,24 @@ void print_syntax(BuildOptions *options)
 		}
 		puts("");
 	}
+	if (options->print_manifest_properties)
+	{
+		int width;
+		puts("Manifest properties");
+		puts("------------------");
+		for (int i = 0; i < manifest_default_keys_count; i++)
+		{
+			printf("%-*s%s\n", 35, manifest_default_keys[i][0], manifest_default_keys[i][1]);
+		}
+		puts("");
+		puts("Target properties");
+		puts("-----------------");
+		for (int i = 0; i < manifest_target_keys_count; i++)
+		{
+			printf("%-*s%s\n", 35, manifest_target_keys[i][0], manifest_target_keys[i][1]);
+		}
+		puts("");
+	}
 	if (options->print_precedence)
 	{
 		puts("precedence     | operators");
diff --git a/src/compiler/compiler_internal.h b/src/compiler/compiler_internal.h
index b508f1dd0..a0e9e4f69 100644
--- a/src/compiler/compiler_internal.h
+++ b/src/compiler/compiler_internal.h
@@ -49,8 +49,12 @@ typedef uint16_t SectionId;
 
 extern const char *project_default_keys[][2];
 extern const int project_default_keys_count;
-extern const char* project_target_keys[][2];
+extern const char *project_target_keys[][2];
 extern const int project_target_keys_count;
+extern const char *manifest_default_keys[][2];
+extern const int manifest_default_keys_count;
+extern const char *manifest_target_keys[][2];
+extern const int manifest_target_keys_count;
 
 typedef struct Ast_ Ast;
 typedef struct Decl_ Decl;