diff --git a/doc/RELEASE-NOTES.md b/doc/RELEASE-NOTES.md
index 7099bcdc3..d5ddbb7b3 100644
--- a/doc/RELEASE-NOTES.md
+++ b/doc/RELEASE-NOTES.md
@@ -120,6 +120,12 @@ has been improved.
   telling the server "does not support remote JSON-RPC".
 
 ### Developers and protocol:
+* If you use `CAP LS` instead of `CAP LS 302` then you will now miss various
+  capabilities. We had to trim it down because only 302 and later allow
+  responses that span multiple lines. If your client is still not using 302
+  then please do so soon (the IRCv3 spec is from Nov'2017). For this first
+  change, you won't miss out much, but somewhere in the future this can
+  become a real problem for you.
 * URL API: The OutgoingWebRequest `max_size` (introduced last release) now
   also caps file-backed downloads. Default for file-backed when left at 0
   is 50MB (`DOWNLOAD_MAX_SIZE_FILE_BACKED`). For memory-backed, it stays
diff --git a/include/modules.h b/include/modules.h
index a466c73c1..8a5e1dfac 100644
--- a/include/modules.h
+++ b/include/modules.h
@@ -517,6 +517,7 @@ struct ClientCapability {
 	MessageTagHandler *mtag_handler;         /**< For reverse dependency */
 	Module *owner;                           /**< Module introducing this CAP. */
 	char unloaded;                           /**< Internal flag to indicate module is being unloaded */
+	int minimum_cap_version;                 /**< Minimum CAP version to show this CAP */
 };
 
 typedef struct {
@@ -524,6 +525,7 @@ typedef struct {
 	int flags;
 	int (*visible)(Client *);
 	const char *(*parameter)(Client *);
+	int minimum_cap_version;
 } ClientCapabilityInfo;
 
 /** @defgroup MessagetagAPI Message tag API
diff --git a/src/api-clicap.c b/src/api-clicap.c
index bb6991c97..5c6060cf2 100644
--- a/src/api-clicap.c
+++ b/src/api-clicap.c
@@ -204,6 +204,7 @@ ClientCapability *ClientCapabilityAdd(Module *module, ClientCapabilityInfo *clic
 	/* Add or update the following fields: */
 	clicap->owner = module;
 	clicap->flags = clicap_request->flags;
+	clicap->minimum_cap_version = clicap_request->minimum_cap_version;
 	clicap->visible = clicap_request->visible;
 	clicap->parameter = clicap_request->parameter;
 
diff --git a/src/modules/cap.c b/src/modules/cap.c
index 0b4a5d01c..f989de702 100644
--- a/src/modules/cap.c
+++ b/src/modules/cap.c
@@ -165,6 +165,9 @@ static void clicap_generate(Client *client, const char *subcmd, int flags)
 		if (cap->visible && !cap->visible(client))
 			continue; /* hidden */
 
+		if (cap->minimum_cap_version && (client->local->cap_protocol < cap->minimum_cap_version))
+			continue; /* skip: doesn't meet minimum CAP version */
+
 		if (flags)
 		{
 			if (!cap->cap || !(client->local->caps & cap->cap))
diff --git a/src/modules/history_backend_mem.c b/src/modules/history_backend_mem.c
index 74f9e928a..6cbbe1c3c 100644
--- a/src/modules/history_backend_mem.c
+++ b/src/modules/history_backend_mem.c
@@ -428,6 +428,7 @@ static void init_history_storage(ModuleInfo *modinfo)
 	cap.name = "unrealircd.org/history-storage";
 	cap.flags = CLICAP_FLAGS_ADVERTISE_ONLY;
 	cap.parameter = history_storage_capability_parameter;
+	cap.minimum_cap_version = 302;
 	ClientCapabilityAdd(modinfo->handle, &cap, NULL);
 }
 
diff --git a/src/modules/json-log-tag.c b/src/modules/json-log-tag.c
index 89d86106b..92e758a01 100644
--- a/src/modules/json-log-tag.c
+++ b/src/modules/json-log-tag.c
@@ -54,6 +54,7 @@ MOD_INIT()
 
 	memset(&cap, 0, sizeof(cap));
 	cap.name = "unrealircd.org/json-log";
+	cap.minimum_cap_version = 302;
 	c = ClientCapabilityAdd(modinfo->handle, &cap, &CAP_JSON_LOG);
 
 	memset(&mtag, 0, sizeof(mtag));
diff --git a/src/modules/link-security.c b/src/modules/link-security.c
index 76e8bed11..30fac0fba 100644
--- a/src/modules/link-security.c
+++ b/src/modules/link-security.c
@@ -80,6 +80,7 @@ MOD_LOAD()
 	cap.name = "unrealircd.org/link-security";
 	cap.flags = CLICAP_FLAGS_ADVERTISE_ONLY;
 	cap.parameter = link_security_capability_parameter;
+	cap.minimum_cap_version = 302;
 	ClientCapabilityAdd(modinfo->handle, &cap, NULL);
 
 	EventAdd(modinfo->handle, "checklinksec", checklinksec, NULL, 2000, 0);
diff --git a/src/modules/plaintext-policy.c b/src/modules/plaintext-policy.c
index d5159d682..dd82b655c 100644
--- a/src/modules/plaintext-policy.c
+++ b/src/modules/plaintext-policy.c
@@ -71,5 +71,6 @@ void init_plaintext_policy(ModuleInfo *modinfo)
 	cap.name = "unrealircd.org/plaintext-policy";
 	cap.flags = CLICAP_FLAGS_ADVERTISE_ONLY;
 	cap.parameter = plaintext_policy_capability_parameter;
+	cap.minimum_cap_version = 302;
 	ClientCapabilityAdd(modinfo->handle, &cap, NULL);
 }