diff --git a/ObjectiveGit/GTIndex.h b/ObjectiveGit/GTIndex.h
index ba57ac2f3..d0df6e4ec 100644
--- a/ObjectiveGit/GTIndex.h
+++ b/ObjectiveGit/GTIndex.h
@@ -155,6 +155,13 @@ NS_ASSUME_NONNULL_BEGIN
 /// Returns whether reading the tree was successful.
 - (BOOL)addContentsOfTree:(GTTree *)tree error:(NSError **)error;
 
+/// Add all the content of the working directory to the index. Like `git add -A`
+///
+/// error - If not NULL, set to any error that occurs.
+///
+/// Returns whether the operation was successful
+- (BOOL)addAll:(NSError **)error;
+
 /// Remove an entry (by relative path) from the index.
 /// Will fail if the receiver's repository is nil.
 ///
diff --git a/ObjectiveGit/GTIndex.m b/ObjectiveGit/GTIndex.m
index 863beb9cc..0acbf0c90 100644
--- a/ObjectiveGit/GTIndex.m
+++ b/ObjectiveGit/GTIndex.m
@@ -218,6 +218,16 @@ - (BOOL)addContentsOfTree:(GTTree *)tree error:(NSError **)error {
 	return YES;
 }
 
+- (BOOL)addAll:(NSError **)error {
+	int status = git_index_add_all(self.git_index, nil, GIT_INDEX_ADD_CHECK_PATHSPEC, nil, nil);
+	if (status != GIT_OK) {
+		if (error != NULL) *error = [NSError git_errorFor:status description:@"Failed to add all the contents of the working tree to the index"];
+		return NO;
+	}
+
+	return YES;
+}
+
 - (BOOL)removeFile:(NSString *)file error:(NSError **)error {
 	NSString *unicodeString = [self composedUnicodeStringWithString:file];
 
diff --git a/ObjectiveGitTests/GTIndexSpec.m b/ObjectiveGitTests/GTIndexSpec.m
index 48b258e8a..1dddd2170 100644
--- a/ObjectiveGitTests/GTIndexSpec.m
+++ b/ObjectiveGitTests/GTIndexSpec.m
@@ -227,6 +227,33 @@
 		renamedFileURL = [NSURL fileURLWithPath:newPath isDirectory:NO];
 	});
 
+	it(@"should add all files from the current file system to the index", ^{
+		NSData *currentFileContent = [[NSFileManager defaultManager] contentsAtPath:fileURL.path];
+		expect(currentFileContent).notTo(beNil());
+		NSString *currentFileString = [[NSString alloc] initWithData:currentFileContent encoding:NSUTF8StringEncoding];
+		currentFileString = [currentFileString stringByAppendingString:@"I would like to append this to the file"];
+		currentFileContent = [currentFileString dataUsingEncoding:NSUTF8StringEncoding];
+		expect(@([[NSFileManager defaultManager] createFileAtPath:fileURL.path contents:currentFileContent attributes:nil])).to(beTruthy());
+
+		NSString *newFileContent = @"This is a new file \n1 2 3";
+		NSData *newFileData = [newFileContent dataUsingEncoding:NSUTF8StringEncoding];
+		expect(newFileData).notTo(beNil());
+		expect(@([[NSFileManager defaultManager] createFileAtPath:renamedFileURL.path contents:newFileData attributes:nil])).to(beTruthy());
+
+		GTIndexEntry *entry = [index entryWithPath:[filename decomposedStringWithCanonicalMapping]];
+		expect(@(fileStatusEqualsExpected(entry.path, GTDeltaTypeUnmodified, GTDeltaTypeModified))).to(beTruthy());
+		entry = [index entryWithPath:[renamedFilename decomposedStringWithCanonicalMapping]];
+		expect(@(fileStatusEqualsExpected(entry.path, GTDeltaTypeUnmodified, GTDeltaTypeUntracked))).to(beTruthy());
+
+		expect(@([index addAll:NULL])).to(beTruthy());
+		expect(@([index write:NULL])).to(beTruthy());
+
+		entry = [index entryWithPath:[filename decomposedStringWithCanonicalMapping]];
+		expect(@(fileStatusEqualsExpected(entry.path, GTDeltaTypeModified, GTDeltaTypeUnmodified))).to(beTruthy());
+		entry = [index entryWithPath:[renamedFilename decomposedStringWithCanonicalMapping]];
+		expect(@(fileStatusEqualsExpected(entry.path, GTDeltaTypeAdded, GTDeltaTypeUnmodified))).to(beTruthy());
+	});
+
 	it(@"it preserves decomposed Unicode in index paths with precomposeunicode disabled", ^{
 		NSString *decomposedFilename = [filename decomposedStringWithCanonicalMapping];
 		GTIndexEntry *entry = [index entryWithPath:decomposedFilename error:NULL];