diff --git a/.tests/parse/file/testfiles/header_invalid.json b/.tests/parse/file/testfiles/header_invalid.json
new file mode 100644
index 0000000..24ff005
--- /dev/null
+++ b/.tests/parse/file/testfiles/header_invalid.json
@@ -0,0 +1,14 @@
+{
+	"name": "A castle",
+	"size": {
+		"x": 50,
+		"y": 25,
+		"z": 75
+	},
+	"offset": {
+		"x": 3,
+		"y": 0,
+		"z": 5
+	},
+	"type": "full",
+	"generator": "WorldEditAdditions v1.14"
diff --git a/.tests/parse/file/testfiles/header_invalid_generator.json b/.tests/parse/file/testfiles/header_invalid_generator.json
new file mode 100644
index 0000000..8ef428e
--- /dev/null
+++ b/.tests/parse/file/testfiles/header_invalid_generator.json
@@ -0,0 +1,15 @@
+{
+	"name": "A castle",
+	"size": {
+		"x": 50,
+		"y": 25,
+		"z": 75
+	},
+	"offset": {
+		"x": 3,
+		"y": 0,
+		"z": 5
+	},
+	"type": "full",
+	"generator": 552323
+}
\ No newline at end of file
diff --git a/.tests/parse/file/testfiles/header_invalid_no_generator.json b/.tests/parse/file/testfiles/header_invalid_no_generator.json
new file mode 100644
index 0000000..f62e207
--- /dev/null
+++ b/.tests/parse/file/testfiles/header_invalid_no_generator.json
@@ -0,0 +1,14 @@
+{
+	"name": "A castle",
+	"size": {
+		"x": 50,
+		"y": 25,
+		"z": 75
+	},
+	"offset": {
+		"x": 3,
+		"y": 0,
+		"z": 5
+	},
+	"type": "full"
+}
\ No newline at end of file
diff --git a/.tests/parse/file/testfiles/header_invalid_no_type.json b/.tests/parse/file/testfiles/header_invalid_no_type.json
new file mode 100644
index 0000000..f65849b
--- /dev/null
+++ b/.tests/parse/file/testfiles/header_invalid_no_type.json
@@ -0,0 +1,14 @@
+{
+	"name": "A castle",
+	"size": {
+		"x": 50,
+		"y": 25,
+		"z": 75
+	},
+	"offset": {
+		"x": 3,
+		"y": 0,
+		"z": 5
+	},
+	"generator": "WorldEditAdditions v1.14"
+}
\ No newline at end of file
diff --git a/.tests/parse/file/testfiles/header_invalid_type.json b/.tests/parse/file/testfiles/header_invalid_type.json
new file mode 100644
index 0000000..41dd19a
--- /dev/null
+++ b/.tests/parse/file/testfiles/header_invalid_type.json
@@ -0,0 +1,15 @@
+{
+	"name": "A castle",
+	"size": {
+		"x": 50,
+		"y": 25,
+		"z": 75
+	},
+	"offset": {
+		"x": 3,
+		"y": 0,
+		"z": 5
+	},
+	"type": 55,
+	"generator": "WorldEditAdditions v1.14"
+}
\ No newline at end of file
diff --git a/.tests/parse/file/testfiles/header_invalid_type_typo.json b/.tests/parse/file/testfiles/header_invalid_type_typo.json
new file mode 100644
index 0000000..ae8d25d
--- /dev/null
+++ b/.tests/parse/file/testfiles/header_invalid_type_typo.json
@@ -0,0 +1,15 @@
+{
+	"name": "A castle",
+	"size": {
+		"x": 50,
+		"y": 25,
+		"z": 75
+	},
+	"offset": {
+		"x": 3,
+		"y": 0,
+		"z": 5
+	},
+	"type": "deltaa",
+	"generator": "WorldEditAdditions v1.14"
+}
\ No newline at end of file
diff --git a/.tests/parse/file/weaschem_header.test.lua b/.tests/parse/file/weaschem_header.test.lua
index 42a2c50..b450228 100644
--- a/.tests/parse/file/weaschem_header.test.lua
+++ b/.tests/parse/file/weaschem_header.test.lua
@@ -23,6 +23,14 @@ describe("parse.file.weaschem.parse_header", function()
 		assert.are.same("SUCCESS", code)
 		assert.are.same(parse_json(content), result)
 	end)
+	it("should not parse a header with a syntax error", function()
+		local content = get_json_string("invalid")
+		assert.are_not.same(nil, content)
+		local success, code, result = weaschem.parse_header(content)
+		assert.are.same(false, success)
+		assert.are.same("HEADER_INVALID_JSON", code)
+		assert.are.same("string", type(result))
+	end)
 	it("should parse a valid header with a description", function()
 		local content = get_json_string("valid2")
 		assert.are_not.same(nil, content)
@@ -87,6 +95,46 @@ describe("parse.file.weaschem.parse_header", function()
 		assert.are.same("HEADER_NO_SIZE", code)
 		assert.are.same("string", type(result))
 	end)
+	it("should complain for an invalid header with no type", function()
+		local content = get_json_string("invalid_no_type")
+		assert.are_not.same(nil, content)
+		local success, code, result = weaschem.parse_header(content)
+		assert.are.same(false, success)
+		assert.are.same("HEADER_NO_TYPE", code)
+		assert.are.same("string", type(result))
+	end)
+	it("should complain for an invalid header with wrong typed type", function()
+		local content = get_json_string("invalid_type")
+		assert.are_not.same(nil, content)
+		local success, code, result = weaschem.parse_header(content)
+		assert.are.same(false, success)
+		assert.are.same("HEADER_TYPE_INVALID", code)
+		assert.are.same("string", type(result))
+	end)
+	it("should complain for an invalid header with typo in type", function()
+		local content = get_json_string("invalid_type_typo")
+		assert.are_not.same(nil, content)
+		local success, code, result = weaschem.parse_header(content)
+		assert.are.same(false, success)
+		assert.are.same("HEADER_TYPE_INVALID", code)
+		assert.are.same("string", type(result))
+	end)
+	it("should complain for invalid header with no generator", function()
+		local content = get_json_string("invalid_no_generator")
+		assert.are_not.same(nil, content)
+		local success, code, result = weaschem.parse_header(content)
+		assert.are.same(false, success)
+		assert.are.same("HEADER_NO_GENERATOR", code)
+		assert.are.same("string", type(result))
+	end)
+	it("should complain for invalid header with generator of wrong type", function()
+		local content = get_json_string("invalid_generator")
+		assert.are_not.same(nil, content)
+		local success, code, result = weaschem.parse_header(content)
+		assert.are.same(false, success)
+		assert.are.same("HEADER_GENERATOR_INVALID", code)
+		assert.are.same("string", type(result))
+	end)
 	
 	-- TODO: Test invalid sizes/offsets, but this is mainly handled by the above
 end)
diff --git a/worldeditadditions_core/utils/parse/file/weaschem.lua b/worldeditadditions_core/utils/parse/file/weaschem.lua
index ae2510a..a012a25 100644
--- a/worldeditadditions_core/utils/parse/file/weaschem.lua
+++ b/worldeditadditions_core/utils/parse/file/weaschem.lua
@@ -45,7 +45,7 @@ end
 
 function weaschem.parse_header(source)
 	local raw_obj = parse_json(source)
-	if raw_obj == nil then return false, "HEADER_INVALID", "The header is invalid JSON." end
+	if raw_obj == nil then return false, "HEADER_INVALID_JSON", "The header is invalid JSON." end
 	
 	local header = {}
 	
@@ -88,7 +88,7 @@ function weaschem.parse_header(source)
 		header["type"] = raw_obj["type"]
 		if type(header["type"]) ~= "string" then
 			return false, "HEADER_TYPE_INVALID",
-				"Invalid type in header: expected string, but found value of type '" .. type(raw_obj["type"]) "'."
+				"Invalid type in header: expected string, but found value of type '" .. type(raw_obj["type"]).."'."
 		end
 		if header["type"] ~= "full" and header["type"] ~= "delta" then
 			return false, "HEADER_TYPE_INVALID",
diff --git a/worldeditadditions_core/utils/parse/json.lua b/worldeditadditions_core/utils/parse/json.lua
index 50021d6..b314a82 100644
--- a/worldeditadditions_core/utils/parse/json.lua
+++ b/worldeditadditions_core/utils/parse/json.lua
@@ -3,10 +3,29 @@ if minetest == nil then
 	json = require("json")
 end
 
+-- Set to true to log JSON parsing errors to stderr when NOT running in Minetest's environment.
+local log_errors_ext = false
+
+local function do_log_error(msg)
+	if log_errors_ext then
+		io.stderr:write(msg)
+	end
+end
+
+local function do_parse_module(source)
+	local success, result = pcall(function() return json.decode(source) end)
+	-- minetest.parse_json doesn't return error messages, so there's no point in return it here either since we can't use this in Minetest's lua environment due to no require().
+	if not success then
+		do_log_error("Error parsing JSON: "..result)
+		return nil
+	end
+	return result
+end
+
 return function(source)
 	if minetest ~= nil then
 		return minetest.parse_json(source)
 	else
-		return json.decode(source)
+		return do_parse_module(source)
 	end
 end
\ No newline at end of file