diff --git a/packages/cohttp-lwt-unix/cohttp-lwt-unix.6.0.0~alpha0/opam b/packages/cohttp-lwt-unix/cohttp-lwt-unix.6.0.0~alpha0/opam
index e74e7a29e82..eb677b1b38a 100644
--- a/packages/cohttp-lwt-unix/cohttp-lwt-unix.6.0.0~alpha0/opam
+++ b/packages/cohttp-lwt-unix/cohttp-lwt-unix.6.0.0~alpha0/opam
@@ -33,8 +33,8 @@ depends: [
   "cohttp-lwt" {= version}
   "cmdliner" {>= "1.1.0"}
   "lwt" {>= "3.0.0"}
-  "conduit-lwt" {>= "5.0.0"}
-  "conduit-lwt-unix" {>= "5.0.0"}
+  "conduit-lwt" {>= "5.0.0" & < "7.0.0"}
+  "conduit-lwt-unix" {>= "5.0.0" & < "7.0.0"}
   "fmt" {>= "0.8.2"}
   "base-unix"
   "ppx_sexp_conv" {>= "v0.13.0"}
diff --git a/packages/cohttp-lwt-unix/cohttp-lwt-unix.6.0.0~alpha1/opam b/packages/cohttp-lwt-unix/cohttp-lwt-unix.6.0.0~alpha1/opam
index 2ac224b59cd..980ddc66ac5 100644
--- a/packages/cohttp-lwt-unix/cohttp-lwt-unix.6.0.0~alpha1/opam
+++ b/packages/cohttp-lwt-unix/cohttp-lwt-unix.6.0.0~alpha1/opam
@@ -33,8 +33,8 @@ depends: [
   "cohttp-lwt" {= version}
   "cmdliner" {>= "1.1.0"}
   "lwt" {>= "3.0.0"}
-  "conduit-lwt" {>= "5.0.0"}
-  "conduit-lwt-unix" {>= "5.0.0"}
+  "conduit-lwt" {>= "5.0.0" & < "7.0.0"}
+  "conduit-lwt-unix" {>= "5.0.0" & < "7.0.0"}
   "fmt" {>= "0.8.2"}
   "base-unix"
   "ppx_sexp_conv" {>= "v0.13.0"}
diff --git a/packages/cohttp-lwt-unix/cohttp-lwt-unix.6.0.0~alpha2/opam b/packages/cohttp-lwt-unix/cohttp-lwt-unix.6.0.0~alpha2/opam
index cf6ead801ff..67ab9ba0d6c 100644
--- a/packages/cohttp-lwt-unix/cohttp-lwt-unix.6.0.0~alpha2/opam
+++ b/packages/cohttp-lwt-unix/cohttp-lwt-unix.6.0.0~alpha2/opam
@@ -33,8 +33,8 @@ depends: [
   "cohttp-lwt" {= version}
   "cmdliner" {>= "1.1.0"}
   "lwt" {>= "3.0.0"}
-  "conduit-lwt" {>= "5.0.0"}
-  "conduit-lwt-unix" {>= "5.0.0"}
+  "conduit-lwt" {>= "5.0.0" & < "7.0.0"}
+  "conduit-lwt-unix" {>= "5.0.0" & < "7.0.0"}
   "fmt" {>= "0.8.2"}
   "base-unix"
   "ppx_sexp_conv" {>= "v0.13.0"}
diff --git a/packages/cohttp-lwt-unix/cohttp-lwt-unix.6.0.0~beta2/opam b/packages/cohttp-lwt-unix/cohttp-lwt-unix.6.0.0~beta2/opam
index 62b6647276f..f94d5e77c67 100644
--- a/packages/cohttp-lwt-unix/cohttp-lwt-unix.6.0.0~beta2/opam
+++ b/packages/cohttp-lwt-unix/cohttp-lwt-unix.6.0.0~beta2/opam
@@ -33,8 +33,8 @@ depends: [
   "cohttp-lwt" {= version}
   "cmdliner" {>= "1.1.0"}
   "lwt" {>= "3.0.0"}
-  "conduit-lwt" {>= "5.0.0"}
-  "conduit-lwt-unix" {>= "5.0.0"}
+  "conduit-lwt" {>= "5.0.0" & < "7.0.0"}
+  "conduit-lwt-unix" {>= "5.0.0" & < "7.0.0"}
   "fmt" {>= "0.8.2"}
   "base-unix"
   "ppx_sexp_conv" {>= "v0.13.0"}
diff --git a/packages/current_web/current_web.0.1/opam b/packages/current_web/current_web.0.1/opam
index 710f0d1bd6c..e9a379d11c6 100644
--- a/packages/current_web/current_web.0.1/opam
+++ b/packages/current_web/current_web.0.1/opam
@@ -27,6 +27,7 @@ depends: [
   "cohttp-lwt-unix" {>= "2.2.0"}
   "tyxml"
   "dune" {>= "1.9"}
+  "conduit" {< "7.0.0"}
 ]
 url {
   src:
diff --git a/packages/current_web/current_web.0.2/opam b/packages/current_web/current_web.0.2/opam
index 3b48dd5c35a..d60ac9ffa03 100644
--- a/packages/current_web/current_web.0.2/opam
+++ b/packages/current_web/current_web.0.2/opam
@@ -28,6 +28,7 @@ depends: [
   "tyxml"
   "routes" {>= "0.7.0" & < "0.8.0"}
   "dune" {>= "1.9"}
+  "conduit" {< "7.0.0"}
 ]
 url {
   src:
diff --git a/packages/current_web/current_web.0.3/opam b/packages/current_web/current_web.0.3/opam
index b7abbb9c906..d75f61de0a6 100644
--- a/packages/current_web/current_web.0.3/opam
+++ b/packages/current_web/current_web.0.3/opam
@@ -33,6 +33,7 @@ depends: [
   "tyxml"
   "routes" {>= "0.8.0" & < "2.0.0"}
   "dune" {>= "2.0"}
+  "conduit" {< "7.0.0"}
 ]
 url {
   src:
diff --git a/packages/websocket/websocket.2.15/opam b/packages/websocket/websocket.2.15/opam
index d384c757bc8..7b608b81eb1 100644
--- a/packages/websocket/websocket.2.15/opam
+++ b/packages/websocket/websocket.2.15/opam
@@ -25,7 +25,7 @@ depends: [
   "dune" {>= "2.9"}
   "ocaml" {>= "4.06.0"}
   "base64" {>= "3.3.0"}
-  "conduit" {>= "5.1.0"}
+  "conduit" {>= "5.1.0" & < "7.0.0"}
   "cohttp" {>= "5.0.0"}
   "ocplib-endian" {>= "1.0"}
   "astring" {>= "0.8.3"}
diff --git a/packages/websocket/websocket.2.16/opam b/packages/websocket/websocket.2.16/opam
index 788b1d72923..260cb2be14e 100644
--- a/packages/websocket/websocket.2.16/opam
+++ b/packages/websocket/websocket.2.16/opam
@@ -25,7 +25,7 @@ depends: [
   "dune" {>= "2.9"}
   "ocaml" {>= "4.06.0"}
   "base64" {>= "3.3.0"}
-  "conduit" {>= "5.1.0"}
+  "conduit" {>= "5.1.0" & < "7.0.0"}
   "cohttp" {>= "5.0.0"}
   "ocplib-endian" {>= "1.0"}
   "astring" {>= "0.8.3"}