diff --git a/src/common/scripting/core/types.h b/src/common/scripting/core/types.h
index 5dc8fd182..380ae88d4 100644
--- a/src/common/scripting/core/types.h
+++ b/src/common/scripting/core/types.h
@@ -111,6 +111,8 @@ public:
 	bool            SizeKnown = true;
 
 	bool			TypeInternal = false;
+	bool			TypeDeprecated = false; // mVersion is deprecation version, not minimum version
+	FString			mDeprecationMessage;
 
 	PType * LocalType = nullptr;
 
diff --git a/src/common/scripting/frontend/zcc-parse.lemon b/src/common/scripting/frontend/zcc-parse.lemon
index c6781db12..eed755355 100644
--- a/src/common/scripting/frontend/zcc-parse.lemon
+++ b/src/common/scripting/frontend/zcc-parse.lemon
@@ -80,6 +80,7 @@ static void SetNodeLine(ZCC_TreeNode *name, int line)
 		ZCC_Identifier *Replaces;
 		ZCC_Identifier *Sealed;
 		VersionInfo Version;
+		FString *DeprecationMessage;
 	};
 
 	struct StateOpts {
@@ -232,6 +233,7 @@ class_head(X) ::= EXTEND CLASS(T) IDENTIFIER(A).
 	head->Version = {0, 0};
 	head->Type = nullptr;
 	head->Symbol = nullptr;
+	head->DeprecationMessage = nullptr;
 	X = head;
 }
 
@@ -247,6 +249,7 @@ class_head(X) ::= CLASS(T) IDENTIFIER(A) class_ancestry(B) class_flags(C).
 	head->Version = C.Version;
 	head->Type = nullptr;
 	head->Symbol = nullptr;
+	head->DeprecationMessage = C.DeprecationMessage;
 	X = head;
 }
 
@@ -255,15 +258,24 @@ class_ancestry(X) ::= .						{ X = NULL; }
 class_ancestry(X) ::= COLON dottable_id(A).	{ X = A; /*X-overwrites-A*/ }
 
 %type class_flags{ClassFlagsBlock}
-class_flags(X) ::= .										{ X.Flags = 0; X.Replaces = NULL; X.Version = {0,0}; X.Sealed = NULL; }
-class_flags(X) ::= class_flags(A) ABSTRACT.					{ X.Flags = A.Flags | ZCC_Abstract; X.Replaces = A.Replaces; X.Version = A.Version; X.Sealed = A.Sealed; }
-class_flags(X) ::= class_flags(A) FINAL.					{ X.Flags = A.Flags | ZCC_Final; X.Replaces = A.Replaces; X.Version = A.Version; X.Sealed =  A.Sealed;}
-class_flags(X) ::= class_flags(A) NATIVE.					{ X.Flags = A.Flags | ZCC_Native; X.Replaces = A.Replaces; X.Version = A.Version; X.Sealed =  A.Sealed; }
-class_flags(X) ::= class_flags(A) UI.						{ X.Flags = A.Flags | ZCC_UIFlag; X.Replaces = A.Replaces; X.Version = A.Version; X.Sealed =  A.Sealed; }
-class_flags(X) ::= class_flags(A) PLAY.						{ X.Flags = A.Flags | ZCC_Play; X.Replaces = A.Replaces; X.Version = A.Version; X.Sealed =  A.Sealed; }
-class_flags(X) ::= class_flags(A) REPLACES dottable_id(B).	{ X.Flags = A.Flags; X.Replaces = B; X.Version = A.Version; X.Sealed = A.Sealed; }
-class_flags(X) ::= class_flags(A) VERSION LPAREN STRCONST(C) RPAREN.	{ X.Flags = A.Flags | ZCC_Version; X.Replaces = A.Replaces; X.Version = C.String->GetChars(); X.Sealed =  A.Sealed; }
-class_flags(X) ::= class_flags(A) SEALED LPAREN states_opt(B) RPAREN.		{ X.Flags = A.Flags | ZCC_Sealed; X.Replaces = A.Replaces; X.Version = A.Version; X.Sealed = B; }
+class_flags(X) ::= .										{ X.Flags = 0; X.Replaces = NULL; X.Version = {0,0}; X.Sealed = NULL; X.DeprecationMessage = NULL; }
+class_flags(X) ::= class_flags(A) ABSTRACT.					{ X.Flags = A.Flags | ZCC_Abstract; X.Replaces = A.Replaces; X.Version = A.Version; X.Sealed = A.Sealed; X.DeprecationMessage = A.DeprecationMessage; }
+class_flags(X) ::= class_flags(A) FINAL.					{ X.Flags = A.Flags | ZCC_Final; X.Replaces = A.Replaces; X.Version = A.Version; X.Sealed = A.Sealed; X.DeprecationMessage = A.DeprecationMessage; }
+class_flags(X) ::= class_flags(A) NATIVE.					{ X.Flags = A.Flags | ZCC_Native; X.Replaces = A.Replaces; X.Version = A.Version; X.Sealed = A.Sealed; X.DeprecationMessage = A.DeprecationMessage; }
+class_flags(X) ::= class_flags(A) UI.						{ X.Flags = A.Flags | ZCC_UIFlag; X.Replaces = A.Replaces; X.Version = A.Version; X.Sealed = A.Sealed; X.DeprecationMessage = A.DeprecationMessage; }
+class_flags(X) ::= class_flags(A) PLAY.						{ X.Flags = A.Flags | ZCC_Play; X.Replaces = A.Replaces; X.Version = A.Version; X.Sealed = A.Sealed; X.DeprecationMessage = A.DeprecationMessage; }
+class_flags(X) ::= class_flags(A) REPLACES dottable_id(B).	{ X.Flags = A.Flags; X.Replaces = B; X.Version = A.Version; X.Sealed = A.Sealed; X.DeprecationMessage = A.DeprecationMessage; }
+class_flags(X) ::= class_flags(A) VERSION LPAREN STRCONST(C) RPAREN.	{ X.Flags = A.Flags | ZCC_Version; X.Replaces = A.Replaces; X.Version = C.String->GetChars(); X.Sealed = A.Sealed; X.DeprecationMessage = A.DeprecationMessage; }
+class_flags(X) ::= class_flags(A) SEALED LPAREN states_opt(B) RPAREN.		{ X.Flags = A.Flags | ZCC_Sealed; X.Replaces = A.Replaces; X.Version = A.Version; X.Sealed = B; X.DeprecationMessage = A.DeprecationMessage; }
+
+class_flags(X) ::= class_flags(A) DEPRECATED LPAREN STRCONST(C) opt_deprecation_message(D) RPAREN.
+{
+	X.Flags = A.Flags | ZCC_Deprecated;
+	X.Replaces = A.Replaces;
+	X.Version = C.String->GetChars();
+	X.Sealed =  A.Sealed;
+	X.DeprecationMessage = D.String;
+}
 
 /*----- Dottable Identifier -----*/
 // This can be either a single identifier or two identifiers connected by a .
@@ -412,6 +424,7 @@ struct_def(X) ::= STRUCT(T) IDENTIFIER(A) struct_flags(S) LBRACE opt_struct_body
 	def->Symbol = nullptr;
 	def->Version = S.Version;
 	def->Flags = S.Flags;
+	def->DeprecationMessage = S.DeprecationMessage;
 	X = def;
 }
 
@@ -422,18 +435,27 @@ struct_def(X) ::= EXTEND STRUCT(T) IDENTIFIER(A) LBRACE opt_struct_body(B) RBRAC
 	def->Body = B;
 	def->Type = nullptr;
 	def->Symbol = nullptr;
+	def->Version = {0, 0};
 	def->Flags = ZCC_Extension;
+	def->DeprecationMessage = nullptr;
 	X = def;
 }
 
 %type struct_flags{ClassFlagsBlock}
-struct_flags(X) ::= .										{ X.Flags = 0; X.Version = {0, 0}; }
-struct_flags(X) ::= struct_flags(A) UI.						{ X.Flags = A.Flags | ZCC_UIFlag; }
-struct_flags(X) ::= struct_flags(A) PLAY.					{ X.Flags = A.Flags | ZCC_Play; }
-struct_flags(X) ::= struct_flags(A) CLEARSCOPE.				{ X.Flags = A.Flags | ZCC_ClearScope; }
-struct_flags(X) ::= struct_flags(A) NATIVE.					{ X.Flags = A.Flags | ZCC_Native; }
-struct_flags(X) ::= struct_flags(A) INTERNAL.				{ X.Flags = A.Flags | ZCC_Internal; }
-struct_flags(X) ::= struct_flags(A) VERSION LPAREN STRCONST(C) RPAREN.	{ X.Flags = A.Flags | ZCC_Version; X.Version = C.String->GetChars(); }
+struct_flags(X) ::= .										{ X.Flags = 0; X.Version = {0, 0}; X.DeprecationMessage = NULL; }
+struct_flags(X) ::= struct_flags(A) UI.						{ X.Flags = A.Flags | ZCC_UIFlag; X.Version = A.Version; X.DeprecationMessage = A.DeprecationMessage; }
+struct_flags(X) ::= struct_flags(A) PLAY.					{ X.Flags = A.Flags | ZCC_Play; X.Version = A.Version; X.DeprecationMessage = A.DeprecationMessage; }
+struct_flags(X) ::= struct_flags(A) CLEARSCOPE.				{ X.Flags = A.Flags | ZCC_ClearScope; X.Version = A.Version; X.DeprecationMessage = A.DeprecationMessage; }
+struct_flags(X) ::= struct_flags(A) NATIVE.					{ X.Flags = A.Flags | ZCC_Native; X.Version = A.Version; X.DeprecationMessage = A.DeprecationMessage; }
+struct_flags(X) ::= struct_flags(A) INTERNAL.				{ X.Flags = A.Flags | ZCC_Internal; X.Version = A.Version; X.DeprecationMessage = A.DeprecationMessage; }
+struct_flags(X) ::= struct_flags(A) VERSION LPAREN STRCONST(C) RPAREN.	{ X.Flags = A.Flags | ZCC_Version; X.Version = C.String->GetChars(); X.DeprecationMessage = A.DeprecationMessage; }
+
+struct_flags(X) ::= struct_flags(A) DEPRECATED LPAREN STRCONST(C) opt_deprecation_message(D) RPAREN.
+{
+	X.Flags = A.Flags | ZCC_Deprecated;
+	X.Version = C.String->GetChars();
+	X.DeprecationMessage = D.String;
+}
 
 opt_struct_body(X) ::= .								{ X = NULL; }
 opt_struct_body(X) ::= struct_body(X).
diff --git a/src/common/scripting/frontend/zcc_compile.cpp b/src/common/scripting/frontend/zcc_compile.cpp
index dfe9dfa13..fb49cf39a 100644
--- a/src/common/scripting/frontend/zcc_compile.cpp
+++ b/src/common/scripting/frontend/zcc_compile.cpp
@@ -751,6 +751,13 @@ void ZCCCompiler::CreateStructTypes()
 			s->strct->Type->mVersion = s->strct->Version;
 		}
 
+		if (s->strct->Flags & ZCC_Deprecated)
+		{
+			s->strct->Type->mVersion = s->strct->Version;
+			s->strct->Type->TypeDeprecated = true;
+			s->strct->Type->mDeprecationMessage = s->strct->DeprecationMessage ? *s->strct->DeprecationMessage : "";
+		}
+
 		if (s->strct->Flags & ZCC_Internal)
 		{
 			s->strct->Type->TypeInternal = true;
@@ -919,6 +926,13 @@ void ZCCCompiler::CreateClassTypes()
 				{
 					c->Type()->mVersion = c->cls->Version;
 				}
+
+				if (c->cls->Flags & ZCC_Deprecated)
+				{
+					c->Type()->mVersion = c->cls->Version;
+					c->Type()->TypeDeprecated = true;
+					c->Type()->mDeprecationMessage = c->cls->DeprecationMessage ? *c->cls->DeprecationMessage : "";
+				}
 				
 
 				if (c->cls->Flags & ZCC_Final)
@@ -2177,7 +2191,16 @@ PType *ZCCCompiler::ResolveUserType(PType *outertype, ZCC_BasicType *type, ZCC_I
 	if (sym != nullptr && sym->IsKindOf(RUNTIME_CLASS(PSymbolType)))
 	{
 		auto ptype = static_cast<PSymbolType *>(sym)->Type;
-		if (ptype->mVersion > mVersion)
+
+		if (ptype->TypeDeprecated)
+		{
+			if(ptype->mVersion <= mVersion && !outertype->TypeDeprecated && fileSystem.GetFileContainer(Lump) > 0)
+			{
+				Warn(type, "Type %s is deprecated since ZScript version %d.%d.%d%s%s",
+					FName(type->UserType->Id).GetChars(), mVersion.major, mVersion.minor, mVersion.revision, ptype->mDeprecationMessage.IsEmpty() ? "" : ": ", ptype->mDeprecationMessage.GetChars());
+			}
+		}
+		else if (ptype->mVersion > mVersion)
 		{
 			Error(type, "Type %s not accessible to ZScript version %d.%d.%d", FName(type->UserType->Id).GetChars(), mVersion.major, mVersion.minor, mVersion.revision);
 			return TypeError;
diff --git a/src/common/scripting/frontend/zcc_parser.h b/src/common/scripting/frontend/zcc_parser.h
index 47ab2d65f..d12d7b87e 100644
--- a/src/common/scripting/frontend/zcc_parser.h
+++ b/src/common/scripting/frontend/zcc_parser.h
@@ -243,6 +243,7 @@ struct ZCC_Struct : ZCC_NamedNode
 	ZCC_TreeNode *Body;
 	PContainerType *Type;
 	VersionInfo Version;
+	FString *DeprecationMessage;
 };
 
 struct ZCC_Property : ZCC_NamedNode
diff --git a/wadsrc/static/zscript/engine/dictionary.zs b/wadsrc/static/zscript/engine/dictionary.zs
index 0bd48cd69..6c778492f 100644
--- a/wadsrc/static/zscript/engine/dictionary.zs
+++ b/wadsrc/static/zscript/engine/dictionary.zs
@@ -5,7 +5,7 @@
  *
  * @note keys are case-sensitive.
  */
-class Dictionary
+class Dictionary deprecated("4.15", "Use Map<String, String> instead")
 {
 	native static Dictionary Create();
 
@@ -38,7 +38,7 @@ class Dictionary
  * DictionaryIterator is not serializable. To make DictionaryIterator a class
  * member, use `transient` keyword.
  */
-class DictionaryIterator
+class DictionaryIterator deprecated("4.15", "Use Map<String, String> instead")
 {
 	native static DictionaryIterator Create(Dictionary dict);