diff --git a/src/config_parser.c b/src/config_parser.c
index 4e66c911..a27cfc5f 100644
--- a/src/config_parser.c
+++ b/src/config_parser.c
@@ -1065,7 +1065,7 @@ bool parse_file(const char *f, bool use_nagbar) {
     int version = detect_version(buf);
     if (version == 3) {
         /* We need to convert this v3 configuration */
-        char *converted = migrate_config(new, stbuf.st_size);
+        char *converted = migrate_config(new, strlen(new));
         if (converted != NULL) {
             ELOG("\n");
             ELOG("****************************************************************\n");
diff --git a/testcases/t/183-config-variables.t b/testcases/t/183-config-variables.t
index 4b225214..d135ed59 100644
--- a/testcases/t/183-config-variables.t
+++ b/testcases/t/183-config-variables.t
@@ -95,7 +95,19 @@ EOT
 
 is(launch_get_border($config), 'none', 'no border');
 
+#####################################################################
+# test that variables with longer name than value don't crash i3 with
+# v3 to v4 conversion.
+# See: #3076
+#####################################################################
 
+$config = <<'EOT';
+set $var a
+EOT
+
+my $pid = launch_with_config($config);
+does_i3_live;
+exit_gracefully($pid);
 
 done_testing;