diff --git a/NEWS b/NEWS
index 6e094e6..5513385 100644
--- a/NEWS
+++ b/NEWS
@@ -1,3 +1,8 @@
+[1.5.0]
+
+Changed default config & state locations to follow the XDG basedir spec.
+The old locations remain supported.
+
 [1.4.0]
 
 The 'isync' compatibility wrapper was removed.
diff --git a/src/config.c b/src/config.c
index 4cb8361..65e080f 100644
--- a/src/config.c
+++ b/src/config.c
@@ -11,6 +11,8 @@
 
 #include <pwd.h>
 #include <ctype.h>
+#include <errno.h>
+#include <sys/stat.h>
 
 #if defined(WIN32) || defined(_WIN32) || defined(__WIN32__) || defined(__NT__) || defined(__CYGWIN__)
 char FieldDelimiter = ';';
@@ -348,12 +350,26 @@ load_config( const char *where )
 	char *arg, *p;
 	uint len, max_size;
 	int cops, gcops, glob_ok, fn, i;
-	char path[_POSIX_PATH_MAX];
+	char path[_POSIX_PATH_MAX], path2[_POSIX_PATH_MAX];
 	char buf[1024];
 
 	if (!where) {
-		nfsnprintf( path, sizeof(path), "%s/." EXE "rc", Home );
-		cfile.file = path;
+		const char *config_home = getenv( "XDG_CONFIG_HOME" );
+		if (config_home)
+			nfsnprintf( path, sizeof(path), "%s/isyncrc", config_home );
+		else
+			nfsnprintf( path, sizeof(path), "%s/.config/isyncrc", Home );
+		nfsnprintf( path2, sizeof(path2), "%s/.mbsyncrc", Home );
+		struct stat st;
+		int ex = !lstat( path, &st );
+		int ex2 = !lstat( path2, &st );
+		if (ex2 && !ex) {
+			cfile.file = path2;
+		} else {
+			if (ex && ex2)
+				warn( "Both %s and %s exist; using the former.\n", path, path2 );
+			cfile.file = path;
+		}
 	} else {
 		cfile.file = where;
 	}
@@ -538,7 +554,25 @@ load_config( const char *where )
 	if (cfile.ms_warn)
 		warn( "Notice: Master/Slave are deprecated; use Far/Near instead.\n" );
 	cfile.err |= merge_ops( gcops, global_conf.ops );
-	if (!global_conf.sync_state)
-		global_conf.sync_state = expand_strdup( "~/." EXE "/" );
+	if (!global_conf.sync_state) {
+		const char *state_home = getenv( "XDG_STATE_HOME" );
+		if (state_home)
+			nfsnprintf( path, sizeof(path), "%s/isync/", state_home );
+		else
+			nfsnprintf( path, sizeof(path), "%s/.local/state/isync/", Home );
+		nfsnprintf( path2, sizeof(path2), "%s/.mbsync/", Home );
+		struct stat st;
+		int ex = !lstat( path, &st );
+		int ex2 = !lstat( path2, &st );
+		if (ex2 && !ex) {
+			global_conf.sync_state = nfstrdup( path2 );
+		} else {
+			if (ex && ex2) {
+				error( "Error: both %s and %s exist; delete one or set SyncState globally.\n", path, path2 );
+				cfile.err = 1;
+			}
+			global_conf.sync_state = nfstrdup( path );
+		}
+	}
 	return cfile.err;
 }
diff --git a/src/mbsync.1 b/src/mbsync.1
index e39aa69..fe08ccf 100644
--- a/src/mbsync.1
+++ b/src/mbsync.1
@@ -32,7 +32,8 @@ Multiple replicas of each mailbox can be maintained.
 .TP
 \fB-c\fR, \fB--config\fR \fIfile\fR
 Read configuration from \fIfile\fR.
-By default, the configuration is read from ~/.mbsyncrc.
+By default, the configuration is read from $XDG_CONFIG_HOME/isyncrc, and
+if that does not exist, ~/.mbsyncrc is tried in turn.
 .TP
 \fB-a\fR, \fB--all\fR
 Select all configured Channels. Any Channel/Group specifications on the
@@ -672,7 +673,8 @@ the appended string is made up according to the pattern
 \fB:\fIfar-store\fB:\fIfar-box\fB_:\fInear-store\fB:\fInear-box\fR
 (see also \fBFieldDelimiter\fR below).
 .br
-(Global default: \fI~/.mbsync/\fR).
+(Global default: \fI$XDG_STATE_HOME/isync/\fR, with a fallback to
+\fI~/.mbsync/\fR if only that exists)
 .
 .SS Groups
 .TP
@@ -795,12 +797,18 @@ There is no risk as long as the IMAP mailbox is accessed by only one client
 .
 .SH FILES
 .TP
-.B ~/.mbsyncrc
+.B $XDG_CONFIG_HOME/isyncrc
 Default configuration file.
 See also the example file in the documentation directory.
 .TP
+.B $XDG_STATE_HOME/isync/
+Directory containing synchronization state files.
+.TP
+.B ~/.mbsyncrc
+Legacy configuration file.
+.TP
 .B ~/.mbsync/
-Directory containing synchronization state files
+Legacy directory containing synchronization state files.
 .
 .SH SEE ALSO
 mdconvert(1), mutt(1), maildir(5)