diff --git a/irmin-bench.opam b/irmin-bench.opam
index f627672386..aa60de9693 100644
--- a/irmin-bench.opam
+++ b/irmin-bench.opam
@@ -28,7 +28,7 @@ depends: [
   "progress"     {>="0.2.1"}
   "fpath"        {with-test}
   "bentov"
-  "mtime"
+  "mtime"        {< "2.0.0"}
   "ppx_deriving"
   "alcotest"     {with-test}
   "rusage"
diff --git a/irmin-containers.opam b/irmin-containers.opam
index f907ec7eb5..672c2acd8f 100644
--- a/irmin-containers.opam
+++ b/irmin-containers.opam
@@ -20,7 +20,7 @@ depends: [
   "irmin-fs"     {= version}
   "ppx_irmin"    {= version}
   "lwt"          {>= "5.3.0"}
-  "mtime"
+  "mtime"        {< "2.0.0"}
   "alcotest"     {with-test}
   "alcotest-lwt" {with-test}
 ]
diff --git a/irmin-git.opam b/irmin-git.opam
index 4c7babac18..5d892b47be 100644
--- a/irmin-git.opam
+++ b/irmin-git.opam
@@ -32,7 +32,7 @@ depends: [
   "uri"
   "mimic"
   "irmin-test" {with-test & = version}
-  "mtime"      {with-test & >= "1.0.0"}
+  "mtime"      {with-test & >= "1.0.0" & < "2.0.0"}
   "alcotest"   {with-test}
   "irmin-watcher" {>= "0.2.0"}
 ]
diff --git a/irmin-pack.opam b/irmin-pack.opam
index a54261716e..14ea2fd8d6 100644
--- a/irmin-pack.opam
+++ b/irmin-pack.opam
@@ -21,7 +21,7 @@ depends: [
   "fmt"
   "logs"
   "lwt"          {>= "5.4.0"}
-  "mtime"
+  "mtime"        {< "2.0.0"}
   "cmdliner"
   "optint"       {>= "0.1.0"}
   "checkseum"
diff --git a/irmin-test.opam b/irmin-test.opam
index bf35ef36c2..58e423b572 100644
--- a/irmin-test.opam
+++ b/irmin-test.opam
@@ -18,7 +18,7 @@ depends: [
   "ocaml"        {>= "4.02.3"}
   "dune"         {>= "2.9.0"}
   "alcotest-lwt" {>= "1.5.0"}
-  "mtime"        {>= "1.0.0"}
+  "mtime"        {>= "1.0.0" & < "2.0.0"}
   "astring"
   "fmt"
   "jsonm"
diff --git a/irmin.opam b/irmin.opam
index d856757316..fe3bf05a5e 100644
--- a/irmin.opam
+++ b/irmin.opam
@@ -27,7 +27,7 @@ depends: [
   "logs"    {>= "0.5.0"}
   "bheap" {>= "2.0.0"}
   "astring"
-  "mtime" {>= "1.0.0"}
+  "mtime" {>= "1.0.0" & < "2.0.0"}
   "bigstringaf" { >= "0.2.0" }
   "ppx_irmin" {= version}
   "hex"      {with-test}