diff --git a/_generated/def.go b/_generated/def.go
index 34cd871e..eac1d5ec 100644
--- a/_generated/def.go
+++ b/_generated/def.go
@@ -63,7 +63,7 @@ type X struct {
 type TestType struct {
 	F   *float64          `msg:"float"`
 	Els map[string]string `msg:"elements"`
-	Obj struct {          // test anonymous struct
+	Obj struct { // test anonymous struct
 		ValueA string `msg:"value_a"`
 		ValueB []byte `msg:"value_b"`
 	} `msg:"object"`
@@ -356,3 +356,21 @@ type Numberwang int8
 type ExternalString string
 type ExternalArr [4]byte
 type ExternalInt int
+
+//msgp:ignore regex:IGNORE
+
+type RegexIGNORETest struct{}
+
+// Will fail to compile if also generated
+func (z *RegexIGNORETest) Msgsize() int {
+	return 0
+}
+
+//msgp:size ignore regex:IGNSIZE
+
+type RegexIGNSIZETest struct{}
+
+// Will fail to compile if also generated
+func (z *RegexIGNSIZETest) Msgsize() int {
+	return 0
+}
diff --git a/gen/spec.go b/gen/spec.go
index 45b514ad..b28f5420 100644
--- a/gen/spec.go
+++ b/gen/spec.go
@@ -5,6 +5,7 @@ import (
 	"fmt"
 	"io"
 	"math"
+	"regexp"
 	"strings"
 )
 
@@ -128,6 +129,19 @@ type TransformPass func(Elem) Elem
 // IgnoreTypename is a pass that just ignores
 // types of a given name.
 func IgnoreTypename(name string) TransformPass {
+	if name, ok := strings.CutPrefix(name, "regex:"); ok {
+		name = strings.TrimPrefix(name, "regex:")
+		rx, err := regexp.Compile(name)
+		if err != nil {
+			panic(fmt.Sprintf("Error compiling ignore regex %q: %v", name, err))
+		}
+		return func(e Elem) Elem {
+			if rx.MatchString(e.TypeName()) {
+				return nil
+			}
+			return e
+		}
+	}
 	return func(e Elem) Elem {
 		if e.TypeName() == name {
 			return nil
@@ -193,17 +207,17 @@ func (c contextVar) Arg() string {
 }
 
 type Context struct {
-	path          []contextItem
-	compFloats    bool
-	clearOmitted  bool
-	newTime       bool
-	asUTC         bool
-	arrayLimit    uint32
-	mapLimit      uint32
-	marshalLimits bool
-	limitPrefix   string
-	currentFieldArrayLimit uint32  // Current field's array limit (0 = no field-level limit)
-	currentFieldMapLimit   uint32  // Current field's map limit (0 = no field-level limit)
+	path                   []contextItem
+	compFloats             bool
+	clearOmitted           bool
+	newTime                bool
+	asUTC                  bool
+	arrayLimit             uint32
+	mapLimit               uint32
+	marshalLimits          bool
+	limitPrefix            string
+	currentFieldArrayLimit uint32 // Current field's array limit (0 = no field-level limit)
+	currentFieldMapLimit   uint32 // Current field's map limit (0 = no field-level limit)
 }
 
 func (c *Context) PushString(s string) {
diff --git a/parse/directives.go b/parse/directives.go
index 09474a6f..05a1597d 100644
--- a/parse/directives.go
+++ b/parse/directives.go
@@ -4,6 +4,7 @@ import (
 	"fmt"
 	"go/ast"
 	"go/parser"
+	"regexp"
 	"strconv"
 	"strings"
 
@@ -167,6 +168,22 @@ func ignore(text []string, f *FileSet) error {
 	}
 	for _, item := range text[1:] {
 		name := strings.TrimSpace(item)
+		if name, ok := strings.CutPrefix(name, "regex:"); ok {
+			name = strings.TrimPrefix(name, "regex:")
+			rx, err := regexp.Compile(name)
+			if err != nil {
+				panic(fmt.Sprintf("Error compiling ignore regex %q: %v", name, err))
+			}
+			for name := range f.Identities {
+				if !rx.MatchString(name) {
+					continue
+				}
+				delete(f.Identities, name)
+				infof("ignoring %s\n", name)
+			}
+			continue
+		}
+
 		if _, ok := f.Identities[name]; ok {
 			delete(f.Identities, name)
 			infof("ignoring %s\n", name)