diff --git a/gen/main.go b/gen/main.go
index ec0b004..f82c120 100644
--- a/gen/main.go
+++ b/gen/main.go
@@ -210,11 +210,11 @@ func generate(typ *def.Class, opt options) string {
 	}
 
 	if opt.cpool {
-		res += emitReadI32()
+		res += emitReadU64()
 		if opt.doNotKeepData {
 
 		} else {
-			res += fmt.Sprintf("id := %s(v32_)\n", refName(typ))
+			res += fmt.Sprintf("id := %s(v64_)\n", refName(typ))
 		}
 	}
 
diff --git a/parser/testdata/cpool-uint64-constant-index.jfr.gz b/parser/testdata/cpool-uint64-constant-index.jfr.gz
new file mode 100644
index 0000000..c4523f7
Binary files /dev/null and b/parser/testdata/cpool-uint64-constant-index.jfr.gz differ
diff --git a/parser/testdata/cpool-uint64-constant-index_0_block_contentions__count delay__nanoseconds_expected.txt.gz b/parser/testdata/cpool-uint64-constant-index_0_block_contentions__count delay__nanoseconds_expected.txt.gz
new file mode 100644
index 0000000..392f3be
Binary files /dev/null and b/parser/testdata/cpool-uint64-constant-index_0_block_contentions__count delay__nanoseconds_expected.txt.gz differ
diff --git a/parser/testdata/cpool-uint64-constant-index_0_block_contentions__count delay__nanoseconds_expected_collapsed.txt.gz b/parser/testdata/cpool-uint64-constant-index_0_block_contentions__count delay__nanoseconds_expected_collapsed.txt.gz
new file mode 100644
index 0000000..576490b
Binary files /dev/null and b/parser/testdata/cpool-uint64-constant-index_0_block_contentions__count delay__nanoseconds_expected_collapsed.txt.gz differ
diff --git a/parser/testdata/cpool-uint64-constant-index_1_memory_alloc_in_new_tlab_objects__count alloc_in_new_tlab_bytes__bytes_expected.txt.gz b/parser/testdata/cpool-uint64-constant-index_1_memory_alloc_in_new_tlab_objects__count alloc_in_new_tlab_bytes__bytes_expected.txt.gz
new file mode 100644
index 0000000..9fa5049
Binary files /dev/null and b/parser/testdata/cpool-uint64-constant-index_1_memory_alloc_in_new_tlab_objects__count alloc_in_new_tlab_bytes__bytes_expected.txt.gz differ
diff --git a/parser/testdata/cpool-uint64-constant-index_1_memory_alloc_in_new_tlab_objects__count alloc_in_new_tlab_bytes__bytes_expected_collapsed.txt.gz b/parser/testdata/cpool-uint64-constant-index_1_memory_alloc_in_new_tlab_objects__count alloc_in_new_tlab_bytes__bytes_expected_collapsed.txt.gz
new file mode 100644
index 0000000..a5ef2d5
Binary files /dev/null and b/parser/testdata/cpool-uint64-constant-index_1_memory_alloc_in_new_tlab_objects__count alloc_in_new_tlab_bytes__bytes_expected_collapsed.txt.gz differ
diff --git a/parser/testdata/cpool-uint64-constant-index_2_memory_alloc_outside_tlab_objects__count alloc_outside_tlab_bytes__bytes_expected.txt.gz b/parser/testdata/cpool-uint64-constant-index_2_memory_alloc_outside_tlab_objects__count alloc_outside_tlab_bytes__bytes_expected.txt.gz
new file mode 100644
index 0000000..86c065a
Binary files /dev/null and b/parser/testdata/cpool-uint64-constant-index_2_memory_alloc_outside_tlab_objects__count alloc_outside_tlab_bytes__bytes_expected.txt.gz differ
diff --git a/parser/testdata/cpool-uint64-constant-index_2_memory_alloc_outside_tlab_objects__count alloc_outside_tlab_bytes__bytes_expected_collapsed.txt.gz b/parser/testdata/cpool-uint64-constant-index_2_memory_alloc_outside_tlab_objects__count alloc_outside_tlab_bytes__bytes_expected_collapsed.txt.gz
new file mode 100644
index 0000000..ef765cc
Binary files /dev/null and b/parser/testdata/cpool-uint64-constant-index_2_memory_alloc_outside_tlab_objects__count alloc_outside_tlab_bytes__bytes_expected_collapsed.txt.gz differ
diff --git a/parser/testdata/cpool-uint64-constant-index_3_process_cpu_cpu__nanoseconds_expected.txt.gz b/parser/testdata/cpool-uint64-constant-index_3_process_cpu_cpu__nanoseconds_expected.txt.gz
new file mode 100644
index 0000000..b545f51
Binary files /dev/null and b/parser/testdata/cpool-uint64-constant-index_3_process_cpu_cpu__nanoseconds_expected.txt.gz differ
diff --git a/parser/testdata/cpool-uint64-constant-index_3_process_cpu_cpu__nanoseconds_expected_collapsed.txt.gz b/parser/testdata/cpool-uint64-constant-index_3_process_cpu_cpu__nanoseconds_expected_collapsed.txt.gz
new file mode 100644
index 0000000..7f35399
Binary files /dev/null and b/parser/testdata/cpool-uint64-constant-index_3_process_cpu_cpu__nanoseconds_expected_collapsed.txt.gz differ
diff --git a/parser/types/class.go b/parser/types/class.go
index 46b805c..72b2302 100644
--- a/parser/types/class.go
+++ b/parser/types/class.go
@@ -90,22 +90,24 @@ func (this *ClassList) Parse(data []byte, bind *BindClass, typeMap *def.TypeMap)
 	this.IDMap = make(map[ClassRef]uint32, n)
 	this.Class = make([]Class, n)
 	for i := 0; i < n; i++ {
-		v32_ = uint32(0)
-		for shift = uint(0); ; shift += 7 {
-			if shift >= 32 {
-				return 0, def.ErrIntOverflow
-			}
+		v64_ = 0
+		for shift = uint(0); shift <= 56; shift += 7 {
 			if pos >= l {
 				return 0, io.ErrUnexpectedEOF
 			}
 			b_ = data[pos]
 			pos++
-			v32_ |= uint32(b_&0x7F) << shift
-			if b_ < 0x80 {
+			if shift == 56 {
+				v64_ |= uint64(b_&0xFF) << shift
 				break
+			} else {
+				v64_ |= uint64(b_&0x7F) << shift
+				if b_ < 0x80 {
+					break
+				}
 			}
 		}
-		id := ClassRef(v32_)
+		id := ClassRef(v64_)
 		for bindFieldIndex := 0; bindFieldIndex < len(bind.Fields); bindFieldIndex++ {
 			bindArraySize := 1
 			if bind.Fields[bindFieldIndex].Field.Array {
diff --git a/parser/types/classloader.go b/parser/types/classloader.go
index 7668e9e..0f5ee84 100644
--- a/parser/types/classloader.go
+++ b/parser/types/classloader.go
@@ -86,22 +86,24 @@ func (this *ClassLoaderList) Parse(data []byte, bind *BindClassLoader, typeMap *
 	this.IDMap = make(map[ClassLoaderRef]uint32, n)
 	this.ClassLoader = make([]ClassLoader, n)
 	for i := 0; i < n; i++ {
-		v32_ = uint32(0)
-		for shift = uint(0); ; shift += 7 {
-			if shift >= 32 {
-				return 0, def.ErrIntOverflow
-			}
+		v64_ = 0
+		for shift = uint(0); shift <= 56; shift += 7 {
 			if pos >= l {
 				return 0, io.ErrUnexpectedEOF
 			}
 			b_ = data[pos]
 			pos++
-			v32_ |= uint32(b_&0x7F) << shift
-			if b_ < 0x80 {
+			if shift == 56 {
+				v64_ |= uint64(b_&0xFF) << shift
 				break
+			} else {
+				v64_ |= uint64(b_&0x7F) << shift
+				if b_ < 0x80 {
+					break
+				}
 			}
 		}
-		id := ClassLoaderRef(v32_)
+		id := ClassLoaderRef(v64_)
 		for bindFieldIndex := 0; bindFieldIndex < len(bind.Fields); bindFieldIndex++ {
 			bindArraySize := 1
 			if bind.Fields[bindFieldIndex].Field.Array {
diff --git a/parser/types/frametype.go b/parser/types/frametype.go
index 48dd699..9d1afda 100644
--- a/parser/types/frametype.go
+++ b/parser/types/frametype.go
@@ -78,22 +78,24 @@ func (this *FrameTypeList) Parse(data []byte, bind *BindFrameType, typeMap *def.
 	this.IDMap = make(map[FrameTypeRef]uint32, n)
 	this.FrameType = make([]FrameType, n)
 	for i := 0; i < n; i++ {
-		v32_ = uint32(0)
-		for shift = uint(0); ; shift += 7 {
-			if shift >= 32 {
-				return 0, def.ErrIntOverflow
-			}
+		v64_ = 0
+		for shift = uint(0); shift <= 56; shift += 7 {
 			if pos >= l {
 				return 0, io.ErrUnexpectedEOF
 			}
 			b_ = data[pos]
 			pos++
-			v32_ |= uint32(b_&0x7F) << shift
-			if b_ < 0x80 {
+			if shift == 56 {
+				v64_ |= uint64(b_&0xFF) << shift
 				break
+			} else {
+				v64_ |= uint64(b_&0x7F) << shift
+				if b_ < 0x80 {
+					break
+				}
 			}
 		}
-		id := FrameTypeRef(v32_)
+		id := FrameTypeRef(v64_)
 		for bindFieldIndex := 0; bindFieldIndex < len(bind.Fields); bindFieldIndex++ {
 			bindArraySize := 1
 			if bind.Fields[bindFieldIndex].Field.Array {
diff --git a/parser/types/loglevel.go b/parser/types/loglevel.go
index 26ba820..3ba3149 100644
--- a/parser/types/loglevel.go
+++ b/parser/types/loglevel.go
@@ -78,22 +78,24 @@ func (this *LogLevelList) Parse(data []byte, bind *BindLogLevel, typeMap *def.Ty
 	this.IDMap = make(map[LogLevelRef]uint32, n)
 	this.LogLevel = make([]LogLevel, n)
 	for i := 0; i < n; i++ {
-		v32_ = uint32(0)
-		for shift = uint(0); ; shift += 7 {
-			if shift >= 32 {
-				return 0, def.ErrIntOverflow
-			}
+		v64_ = 0
+		for shift = uint(0); shift <= 56; shift += 7 {
 			if pos >= l {
 				return 0, io.ErrUnexpectedEOF
 			}
 			b_ = data[pos]
 			pos++
-			v32_ |= uint32(b_&0x7F) << shift
-			if b_ < 0x80 {
+			if shift == 56 {
+				v64_ |= uint64(b_&0xFF) << shift
 				break
+			} else {
+				v64_ |= uint64(b_&0x7F) << shift
+				if b_ < 0x80 {
+					break
+				}
 			}
 		}
-		id := LogLevelRef(v32_)
+		id := LogLevelRef(v64_)
 		for bindFieldIndex := 0; bindFieldIndex < len(bind.Fields); bindFieldIndex++ {
 			bindArraySize := 1
 			if bind.Fields[bindFieldIndex].Field.Array {
diff --git a/parser/types/method.go b/parser/types/method.go
index 6fd375a..4706f62 100644
--- a/parser/types/method.go
+++ b/parser/types/method.go
@@ -97,22 +97,24 @@ func (this *MethodList) Parse(data []byte, bind *BindMethod, typeMap *def.TypeMa
 	this.IDMap = NewIDMap[MethodRef](n)
 	this.Method = make([]Method, n)
 	for i := 0; i < n; i++ {
-		v32_ = uint32(0)
-		for shift = uint(0); ; shift += 7 {
-			if shift >= 32 {
-				return 0, def.ErrIntOverflow
-			}
+		v64_ = 0
+		for shift = uint(0); shift <= 56; shift += 7 {
 			if pos >= l {
 				return 0, io.ErrUnexpectedEOF
 			}
 			b_ = data[pos]
 			pos++
-			v32_ |= uint32(b_&0x7F) << shift
-			if b_ < 0x80 {
+			if shift == 56 {
+				v64_ |= uint64(b_&0xFF) << shift
 				break
+			} else {
+				v64_ |= uint64(b_&0x7F) << shift
+				if b_ < 0x80 {
+					break
+				}
 			}
 		}
-		id := MethodRef(v32_)
+		id := MethodRef(v64_)
 		for bindFieldIndex := 0; bindFieldIndex < len(bind.Fields); bindFieldIndex++ {
 			bindArraySize := 1
 			if bind.Fields[bindFieldIndex].Field.Array {
diff --git a/parser/types/package.go b/parser/types/package.go
index d061ede..b78b2ae 100644
--- a/parser/types/package.go
+++ b/parser/types/package.go
@@ -78,22 +78,24 @@ func (this *PackageList) Parse(data []byte, bind *BindPackage, typeMap *def.Type
 	this.IDMap = make(map[PackageRef]uint32, n)
 	this.Package = make([]Package, n)
 	for i := 0; i < n; i++ {
-		v32_ = uint32(0)
-		for shift = uint(0); ; shift += 7 {
-			if shift >= 32 {
-				return 0, def.ErrIntOverflow
-			}
+		v64_ = 0
+		for shift = uint(0); shift <= 56; shift += 7 {
 			if pos >= l {
 				return 0, io.ErrUnexpectedEOF
 			}
 			b_ = data[pos]
 			pos++
-			v32_ |= uint32(b_&0x7F) << shift
-			if b_ < 0x80 {
+			if shift == 56 {
+				v64_ |= uint64(b_&0xFF) << shift
 				break
+			} else {
+				v64_ |= uint64(b_&0x7F) << shift
+				if b_ < 0x80 {
+					break
+				}
 			}
 		}
-		id := PackageRef(v32_)
+		id := PackageRef(v64_)
 		for bindFieldIndex := 0; bindFieldIndex < len(bind.Fields); bindFieldIndex++ {
 			bindArraySize := 1
 			if bind.Fields[bindFieldIndex].Field.Array {
diff --git a/parser/types/skipper.go b/parser/types/skipper.go
index 701fe1b..3651e3d 100644
--- a/parser/types/skipper.go
+++ b/parser/types/skipper.go
@@ -66,19 +66,21 @@ func (this *SkipConstantPoolList) Parse(data []byte, bind *BindSkipConstantPool,
 	}
 	n := int(v32_)
 	for i := 0; i < n; i++ {
-		v32_ = uint32(0)
-		for shift = uint(0); ; shift += 7 {
-			if shift >= 32 {
-				return 0, def.ErrIntOverflow
-			}
+		v64_ = 0
+		for shift = uint(0); shift <= 56; shift += 7 {
 			if pos >= l {
 				return 0, io.ErrUnexpectedEOF
 			}
 			b_ = data[pos]
 			pos++
-			v32_ |= uint32(b_&0x7F) << shift
-			if b_ < 0x80 {
+			if shift == 56 {
+				v64_ |= uint64(b_&0xFF) << shift
 				break
+			} else {
+				v64_ |= uint64(b_&0x7F) << shift
+				if b_ < 0x80 {
+					break
+				}
 			}
 		}
 		for bindFieldIndex := 0; bindFieldIndex < len(bind.Fields); bindFieldIndex++ {
diff --git a/parser/types/stacktrace.go b/parser/types/stacktrace.go
index 38a0caf..3b7cd42 100644
--- a/parser/types/stacktrace.go
+++ b/parser/types/stacktrace.go
@@ -86,22 +86,24 @@ func (this *StackTraceList) Parse(data []byte, bind *BindStackTrace, bindStackFr
 	this.IDMap = make(map[StackTraceRef]uint32, n)
 	this.StackTrace = make([]StackTrace, n)
 	for i := 0; i < n; i++ {
-		v32_ = uint32(0)
-		for shift = uint(0); ; shift += 7 {
-			if shift >= 32 {
-				return 0, def.ErrIntOverflow
-			}
+		v64_ = 0
+		for shift = uint(0); shift <= 56; shift += 7 {
 			if pos >= l {
 				return 0, io.ErrUnexpectedEOF
 			}
 			b_ = data[pos]
 			pos++
-			v32_ |= uint32(b_&0x7F) << shift
-			if b_ < 0x80 {
+			if shift == 56 {
+				v64_ |= uint64(b_&0xFF) << shift
 				break
+			} else {
+				v64_ |= uint64(b_&0x7F) << shift
+				if b_ < 0x80 {
+					break
+				}
 			}
 		}
-		id := StackTraceRef(v32_)
+		id := StackTraceRef(v64_)
 		for bindFieldIndex := 0; bindFieldIndex < len(bind.Fields); bindFieldIndex++ {
 			bindArraySize := 1
 			if bind.Fields[bindFieldIndex].Field.Array {
diff --git a/parser/types/symbol.go b/parser/types/symbol.go
index dbab2bd..cc69892 100644
--- a/parser/types/symbol.go
+++ b/parser/types/symbol.go
@@ -78,22 +78,24 @@ func (this *SymbolList) Parse(data []byte, bind *BindSymbol, typeMap *def.TypeMa
 	this.IDMap = make(map[SymbolRef]uint32, n)
 	this.Symbol = make([]Symbol, n)
 	for i := 0; i < n; i++ {
-		v32_ = uint32(0)
-		for shift = uint(0); ; shift += 7 {
-			if shift >= 32 {
-				return 0, def.ErrIntOverflow
-			}
+		v64_ = 0
+		for shift = uint(0); shift <= 56; shift += 7 {
 			if pos >= l {
 				return 0, io.ErrUnexpectedEOF
 			}
 			b_ = data[pos]
 			pos++
-			v32_ |= uint32(b_&0x7F) << shift
-			if b_ < 0x80 {
+			if shift == 56 {
+				v64_ |= uint64(b_&0xFF) << shift
 				break
+			} else {
+				v64_ |= uint64(b_&0x7F) << shift
+				if b_ < 0x80 {
+					break
+				}
 			}
 		}
-		id := SymbolRef(v32_)
+		id := SymbolRef(v64_)
 		for bindFieldIndex := 0; bindFieldIndex < len(bind.Fields); bindFieldIndex++ {
 			bindArraySize := 1
 			if bind.Fields[bindFieldIndex].Field.Array {
diff --git a/parser/types/thread.go b/parser/types/thread.go
index 75a3220..b2ee7c0 100644
--- a/parser/types/thread.go
+++ b/parser/types/thread.go
@@ -100,22 +100,24 @@ func (this *ThreadList) Parse(data []byte, bind *BindThread, typeMap *def.TypeMa
 	this.IDMap = make(map[ThreadRef]uint32, n)
 	this.Thread = make([]Thread, n)
 	for i := 0; i < n; i++ {
-		v32_ = uint32(0)
-		for shift = uint(0); ; shift += 7 {
-			if shift >= 32 {
-				return 0, def.ErrIntOverflow
-			}
+		v64_ = 0
+		for shift = uint(0); shift <= 56; shift += 7 {
 			if pos >= l {
 				return 0, io.ErrUnexpectedEOF
 			}
 			b_ = data[pos]
 			pos++
-			v32_ |= uint32(b_&0x7F) << shift
-			if b_ < 0x80 {
+			if shift == 56 {
+				v64_ |= uint64(b_&0xFF) << shift
 				break
+			} else {
+				v64_ |= uint64(b_&0x7F) << shift
+				if b_ < 0x80 {
+					break
+				}
 			}
 		}
-		id := ThreadRef(v32_)
+		id := ThreadRef(v64_)
 		for bindFieldIndex := 0; bindFieldIndex < len(bind.Fields); bindFieldIndex++ {
 			bindArraySize := 1
 			if bind.Fields[bindFieldIndex].Field.Array {
diff --git a/parser/types/threadstate.go b/parser/types/threadstate.go
index 0c533e2..7d46519 100644
--- a/parser/types/threadstate.go
+++ b/parser/types/threadstate.go
@@ -78,22 +78,24 @@ func (this *ThreadStateList) Parse(data []byte, bind *BindThreadState, typeMap *
 	this.IDMap = make(map[ThreadStateRef]uint32, n)
 	this.ThreadState = make([]ThreadState, n)
 	for i := 0; i < n; i++ {
-		v32_ = uint32(0)
-		for shift = uint(0); ; shift += 7 {
-			if shift >= 32 {
-				return 0, def.ErrIntOverflow
-			}
+		v64_ = 0
+		for shift = uint(0); shift <= 56; shift += 7 {
 			if pos >= l {
 				return 0, io.ErrUnexpectedEOF
 			}
 			b_ = data[pos]
 			pos++
-			v32_ |= uint32(b_&0x7F) << shift
-			if b_ < 0x80 {
+			if shift == 56 {
+				v64_ |= uint64(b_&0xFF) << shift
 				break
+			} else {
+				v64_ |= uint64(b_&0x7F) << shift
+				if b_ < 0x80 {
+					break
+				}
 			}
 		}
-		id := ThreadStateRef(v32_)
+		id := ThreadStateRef(v64_)
 		for bindFieldIndex := 0; bindFieldIndex < len(bind.Fields); bindFieldIndex++ {
 			bindArraySize := 1
 			if bind.Fields[bindFieldIndex].Field.Array {
diff --git a/pprof/parser_test.go b/pprof/parser_test.go
index 4607e4f..60d00e7 100644
--- a/pprof/parser_test.go
+++ b/pprof/parser_test.go
@@ -44,6 +44,7 @@ var testfiles = []testdata{
 	{"dump1", "dump1.labels.pb.gz", 1},
 	{"dump2", "dump2.labels.pb.gz", 4},
 	{"dd-trace-java", "", 4},
+	{"cpool-uint64-constant-index", "", 4},
 }
 
 type gprofile struct {