diff --git a/handlers/aliases/lsp/text-document-signature-help.go b/handlers/aliases/lsp/text-document-signature-help.go
index ce3a9b0..6408f50 100644
--- a/handlers/aliases/lsp/text-document-signature-help.go
+++ b/handlers/aliases/lsp/text-document-signature-help.go
@@ -1,6 +1,7 @@
 package lsp
 
 import (
+	"config-lsp/common"
 	"config-lsp/handlers/aliases"
 	"config-lsp/handlers/aliases/ast"
 	"config-lsp/handlers/aliases/handlers"
@@ -13,7 +14,7 @@ func TextDocumentSignatureHelp(context *glsp.Context, params *protocol.Signature
 	document := aliases.DocumentParserMap[params.TextDocument.URI]
 
 	line := params.Position.Line
-	character := params.Position.Character
+	character := common.CursorToCharacterIndex(params.Position.Character)
 
 	if _, found := document.Parser.CommentLines[line]; found {
 		// Comment
diff --git a/handlers/sshd_config/Config.g4 b/handlers/sshd_config/Config.g4
index 569a6a8..ad4cbe8 100644
--- a/handlers/sshd_config/Config.g4
+++ b/handlers/sshd_config/Config.g4
@@ -1,7 +1,7 @@
 grammar Config;
 
 lineStatement
-    : (entry | (leadingComment) | WHITESPACE?) EOF
+    : (entry | leadingComment | WHITESPACE?) EOF
     ;
 
 entry
diff --git a/handlers/sshd_config/analyzer/analyzer.go b/handlers/sshd_config/analyzer/analyzer.go
index 0b661c6..36944aa 100644
--- a/handlers/sshd_config/analyzer/analyzer.go
+++ b/handlers/sshd_config/analyzer/analyzer.go
@@ -49,6 +49,8 @@ func Analyze(
 		}
 	}
 
+	errors = append(errors, analyzeMatchBlocks(d)...)
+
 	if len(errors) > 0 {
 		return errsToDiagnostics(errors)
 	}
diff --git a/handlers/sshd_config/analyzer/match.go b/handlers/sshd_config/analyzer/match.go
new file mode 100644
index 0000000..c5ad800
--- /dev/null
+++ b/handlers/sshd_config/analyzer/match.go
@@ -0,0 +1,112 @@
+package analyzer
+
+import (
+	"config-lsp/common"
+	sshdconfig "config-lsp/handlers/sshd_config"
+	match_parser "config-lsp/handlers/sshd_config/fields/match-parser"
+	"config-lsp/utils"
+	"errors"
+	"fmt"
+	"strings"
+)
+
+func analyzeMatchBlocks(
+	d *sshdconfig.SSHDocument,
+) []common.LSPError {
+	errs := make([]common.LSPError, 0)
+
+	for _, indexOption := range d.Indexes.AllOptionsPerName["Match"] {
+		matchBlock := indexOption.MatchBlock.MatchValue
+
+		// Check if the match block has filled out all fields
+		if matchBlock == nil || len(matchBlock.Entries) == 0 {
+			errs = append(errs, common.LSPError{
+				Range: indexOption.Option.LocationRange,
+				Err:   errors.New("A match expression is required"),
+			})
+			continue
+		}
+
+		for _, entry := range matchBlock.Entries {
+			if entry.Values == nil {
+				errs = append(errs, common.LSPError{
+					Range: entry.LocationRange,
+					Err:   errors.New(fmt.Sprintf("A value for %s is required", entry.Criteria.Type)),
+				})
+			} else {
+				errs = append(errs, analyzeMatchValuesContainsPositiveValue(entry.Values)...)
+
+				for _, value := range entry.Values.Values {
+					errs = append(errs, analyzeMatchValueNegation(value)...)
+				}
+			}
+		}
+
+		// Check if match blocks are not empty
+		if indexOption.MatchBlock.Options.Size() == 0 {
+			errs = append(errs, common.LSPError{
+				Range: indexOption.Option.LocationRange,
+				Err:   errors.New("This match block is empty"),
+			})
+		}
+	}
+
+	return errs
+}
+
+func analyzeMatchValueNegation(
+	value *match_parser.MatchValue,
+) []common.LSPError {
+	errs := make([]common.LSPError, 0)
+
+	positionsAsList := utils.AllIndexes(value.Value, "!")
+	positions := utils.SliceToMap(positionsAsList, struct{}{})
+
+	delete(positions, 0)
+
+	for position := range positions {
+		errs = append(errs, common.LSPError{
+			Range: common.LocationRange{
+				Start: common.Location{
+					Line:      value.Start.Line,
+					Character: uint32(position) + value.Start.Character,
+				},
+				End: common.Location{
+					Line:      value.End.Line,
+					Character: uint32(position) + value.End.Character,
+				},
+			},
+			Err: errors.New("The negation operator (!) may only occur at the beginning of a value"),
+		})
+	}
+
+	return errs
+}
+
+func analyzeMatchValuesContainsPositiveValue(
+	values *match_parser.MatchValues,
+) []common.LSPError {
+	if len(values.Values) == 0 {
+		return nil
+	}
+
+	containsPositive := false
+
+	for _, value := range values.Values {
+		if !strings.HasPrefix(value.Value, "!") {
+			containsPositive = true
+			break
+		}
+	}
+
+	if !containsPositive {
+		return []common.LSPError{
+			{
+				Range: values.LocationRange,
+				Err:   errors.New("At least one positive value is required. A negated match will never produce a positive result by itself"),
+			},
+		}
+	}
+
+	return nil
+}
diff --git a/handlers/sshd_config/analyzer/match_test.go b/handlers/sshd_config/analyzer/match_test.go
new file mode 100644
index 0000000..b65b478
--- /dev/null
+++ b/handlers/sshd_config/analyzer/match_test.go
@@ -0,0 +1,63 @@
+package analyzer
+
+import (
+	sshdconfig "config-lsp/handlers/sshd_config"
+	"config-lsp/handlers/sshd_config/ast"
+	"config-lsp/handlers/sshd_config/indexes"
+	"config-lsp/utils"
+	"testing"
+)
+
+func TestEmptyMatchBlocksMakesErrors(
+	t *testing.T,
+) {
+	input := utils.Dedent(`
+PermitRootLogin yes
+Match User root
+`)
+	c := ast.NewSSHConfig()
+	errors := c.Parse(input)
+
+	if len(errors) > 0 {
+		t.Fatalf("Parse error: %v", errors)
+	}
+
+	indexes, errors := indexes.CreateIndexes(*c)
+
+	if len(errors) > 0 {
+		t.Fatalf("Index error: %v", errors)
+	}
+
+	d := &sshdconfig.SSHDocument{
+		Config:  c,
+		Indexes: indexes,
+	}
+
+	errors = analyzeMatchBlocks(d)
+
+	if !(len(errors) == 1) {
+		t.Errorf("Expected 1 error, got %v", len(errors))
+	}
+}
+
+func TestContainsOnlyNegativeValues(
+	t *testing.T,
+) {
+	input := utils.Dedent(`
+PermitRootLogin yes
+Match User !root,!admin
+`)
+	c := ast.NewSSHConfig()
+	errors := c.Parse(input)
+
+	if len(errors) > 0 {
+		t.Fatalf("Parse error: %v", errors)
+	}
+
+	_, matchBlock := c.FindOption(uint32(1))
+	errors = analyzeMatchValuesContainsPositiveValue(matchBlock.MatchValue.Entries[0].Values)
+
+	if !(len(errors) == 1) {
+		t.Errorf("Expected 1 error, got %v", len(errors))
+	}
+}
diff --git a/handlers/sshd_config/ast/listener.go b/handlers/sshd_config/ast/listener.go
index b5c81b2..4830005 100644
--- a/handlers/sshd_config/ast/listener.go
+++ b/handlers/sshd_config/ast/listener.go
@@ -93,6 +93,10 @@ func (s *sshParserListener) ExitEntry(ctx *parser.EntryContext) {
 	location := common.CharacterRangeFromCtx(ctx.BaseParserRuleContext)
 	location.ChangeBothLines(s.sshContext.line)
 
+	defer (func() {
+		s.sshContext.currentOption = nil
+	})()
+
 	if s.sshContext.isKeyAMatchBlock {
 		// Add new match block
 		var match *match_parser.Match
@@ -131,17 +135,20 @@ func (s *sshParserListener) ExitEntry(ctx *parser.EntryContext) {
 		s.sshContext.currentMatchBlock = matchBlock
 
 		s.sshContext.isKeyAMatchBlock = false
-	} else if s.sshContext.currentMatchBlock != nil {
+
+		return
+	}
+
+	if s.sshContext.currentMatchBlock != nil {
 		s.sshContext.currentMatchBlock.Options.Put(
 			location.Start.Line,
 			s.sshContext.currentOption,
 		)
+		s.sshContext.currentMatchBlock.End = s.sshContext.currentOption.End
 	} else {
 		s.Config.Options.Put(
 			location.Start.Line,
 			s.sshContext.currentOption,
 		)
 	}
-
-	s.sshContext.currentOption = nil
 }
diff --git a/handlers/sshd_config/ast/parser_test.go b/handlers/sshd_config/ast/parser_test.go
index e883966..63d5bb0 100644
--- a/handlers/sshd_config/ast/parser_test.go
+++ b/handlers/sshd_config/ast/parser_test.go
@@ -92,6 +92,10 @@ Match Address 192.168.0.1
 		t.Errorf("Expected second entry to be 'Match Address 192.168.0.1', but got: %v", secondEntry.MatchEntry.Value)
 	}
 
+	if !(secondEntry.Start.Line == 2 && secondEntry.Start.Character == 0 && secondEntry.End.Line == 3 && secondEntry.End.Character == 26) {
+		t.Errorf("Expected second entry's location to be 2:0-3:25, but got: %v", secondEntry.LocationRange)
+	}
+
 	if !(secondEntry.MatchValue.Entries[0].Criteria.Type == "Address" && secondEntry.MatchValue.Entries[0].Values.Values[0].Value == "192.168.0.1" && secondEntry.MatchEntry.OptionValue.Start.Character == 6) {
 		t.Errorf("Expected second entry to be 'Match Address 192.168.0.1', but got: %v", secondEntry.MatchValue)
 	}
@@ -235,6 +239,17 @@ Match Address 192.168.0.2
 	if !(matchOption.Value == "Match User lena" && matchBlock.MatchEntry.Value == "Match User lena" && matchBlock.MatchValue.Entries[0].Values.Values[0].Value == "lena" && matchBlock.MatchEntry.OptionValue.Start.Character == 6) {
 		t.Errorf("Expected match option to be 'Match User lena', but got: %v, %v", matchOption, matchBlock)
 	}
+
+	if !(matchOption.Start.Line == 2 && matchOption.End.Line == 2 && matchOption.Start.Character == 0 && matchOption.End.Character == 14) {
+		t.Errorf("Expected match option to be at 2:0-14, but got: %v", matchOption.LocationRange)
+	}
+
+	if !(matchBlock.Start.Line == 2 &&
+		matchBlock.Start.Character == 0 &&
+		matchBlock.End.Line == 4 &&
+		matchBlock.End.Character == 20) {
+		t.Errorf("Expected match block to be at 2:0-4:20, but got: %v", matchBlock.LocationRange)
+	}
 }
 
 func TestSimpleExampleWithComments(
diff --git a/handlers/sshd_config/handlers/completions_match.go b/handlers/sshd_config/handlers/completions_match.go
index 4a6fa2f..6a10ebe 100644
--- a/handlers/sshd_config/handlers/completions_match.go
+++ b/handlers/sshd_config/handlers/completions_match.go
@@ -13,7 +13,7 @@ func getMatchCompletions(
 	match *match_parser.Match,
 	cursor uint32,
 ) ([]protocol.CompletionItem, error) {
-	if len(match.Entries) == 0 {
+	if match == nil || len(match.Entries) == 0 {
 		completions := getMatchCriteriaCompletions()
 		completions = append(completions, getMatchAllKeywordCompletion())
 
diff --git a/handlers/sshd_config/indexes/indexes.go b/handlers/sshd_config/indexes/indexes.go
index ed56afd..ebdda30 100644
--- a/handlers/sshd_config/indexes/indexes.go
+++ b/handlers/sshd_config/indexes/indexes.go
@@ -82,6 +82,8 @@ func CreateIndexes(config ast.SSHConfig) (*SSHIndexes, []common.LSPError) {
 		case *ast.SSHMatchBlock:
 			matchBlock := entry.(*ast.SSHMatchBlock)
 
+			errs = append(errs, addOption(indexes, matchBlock.MatchEntry, matchBlock)...)
+
 			it := matchBlock.Options.Iterator()
 			for it.Next() {
 				option := it.Value().(*ast.SSHOption)
diff --git a/root-handler/handler.go b/root-handler/handler.go
index 4a7cd3c..fc59b8a 100644
--- a/root-handler/handler.go
+++ b/root-handler/handler.go
@@ -42,15 +42,7 @@ func SetUpRootHandler() {
 func initialize(context *glsp.Context, params *protocol.InitializeParams) (any, error) {
 	capabilities := lspHandler.CreateServerCapabilities()
 	capabilities.TextDocumentSync = protocol.TextDocumentSyncKindFull
-	capabilities.SignatureHelpProvider = &protocol.SignatureHelpOptions{
-		TriggerCharacters: []string{
-			"a", "b", "c", "d", "e", "f", "g", "h", "i", "j", "k", "l", "m", "n", "o", "p", "q", "r", "s", "t", "u", "v", "w", "x", "y", "z",
-			"A", "B", "C", "D", "E", "F", "G", "H", "I", "J", "K", "L", "M", "N", "O", "P", "Q", "R", "S", "T", "U", "V", "W", "X", "Y", "Z",
-			"0", "1", "2", "3", "4", "5", "6", "7", "8", "9",
-			"_", "-", ".", "/", ":", "@", "#", "!", "$", "%", "^", "&", "*", "(", ")", "+", "=", "[", "]", "{", "}", "<", ">", "?", ";", ",", "|",
-			" ",
-		},
-	}
+	capabilities.SignatureHelpProvider = &protocol.SignatureHelpOptions{}
 
 	if (*params.Capabilities.TextDocument.Rename.PrepareSupport) == true {
 		// Client supports rename preparation
diff --git a/utils/strings.go b/utils/strings.go
index bc32f88..3f7f851 100644
--- a/utils/strings.go
+++ b/utils/strings.go
@@ -2,6 +2,7 @@ package utils
 
 import (
 	"regexp"
+	"strings"
 )
 
 var trimIndexPattern = regexp.MustCompile(`^\s*(.+?)\s*$`)
@@ -57,3 +58,21 @@ var emptyRegex = regexp.MustCompile(`^\s*$`)
 func IsEmpty(s string) bool {
 	return emptyRegex.MatchString(s)
 }
+
+func AllIndexes(s string, sub string) []int {
+	indexes := make([]int, 0)
+	current := s
+
+	for {
+		index := strings.Index(current, sub)
+
+		if index == -1 {
+			break
+		}
+
+		indexes = append(indexes, index)
+		current = current[index+1:]
+	}
+
+	return indexes
+}