diff --git a/eth/db/kvstore.nim b/eth/db/kvstore.nim
index e8fb294..3b54d37 100644
--- a/eth/db/kvstore.nim
+++ b/eth/db/kvstore.nim
@@ -8,7 +8,12 @@
 ## Simple Key-Value store database interface that allows creating multiple
 ## tables within each store
 
-{.push raises: [Defect].}
+when (NimMajor, NimMinor) < (1, 4):
+  {.push raises: [Defect].}
+  {.pragma: callback, gcsafe, raises: [Defect].}
+else:
+  {.push raises: [].}
+  {.pragma: callback, gcsafe, raises: [].}
 
 import
   std/[tables, hashes, sets],
@@ -25,16 +30,16 @@ type
 
   KvResult*[T] = Result[T, string]
 
-  DataProc* = proc(val: openArray[byte]) {.gcsafe, raises: [Defect].}
-  KeyValueProc* = proc(key, val: openArray[byte]) {.gcsafe, raises: [Defect].}
+  DataProc* = proc(val: openArray[byte]) {.callback.}
+  KeyValueProc* = proc(key, val: openArray[byte]) {.callback.}
 
-  PutProc = proc (db: RootRef, key, val: openArray[byte]): KvResult[void] {.nimcall, gcsafe, raises: [Defect].}
-  GetProc = proc (db: RootRef, key: openArray[byte], onData: DataProc): KvResult[bool] {.nimcall, gcsafe, raises: [Defect].}
-  FindProc = proc (db: RootRef, prefix: openArray[byte], onFind: KeyValueProc): KvResult[int] {.nimcall, gcsafe, raises: [Defect].}
-  DelProc = proc (db: RootRef, key: openArray[byte]): KvResult[bool] {.nimcall, gcsafe, raises: [Defect].}
-  ClearProc = proc (db: RootRef): KvResult[bool] {.nimcall, gcsafe, raises: [Defect].}
-  ContainsProc = proc (db: RootRef, key: openArray[byte]): KvResult[bool] {.nimcall, gcsafe, raises: [Defect].}
-  CloseProc = proc (db: RootRef): KvResult[void] {.nimcall, gcsafe, raises: [Defect].}
+  PutProc = proc (db: RootRef, key, val: openArray[byte]): KvResult[void] {.nimcall, callback.}
+  GetProc = proc (db: RootRef, key: openArray[byte], onData: DataProc): KvResult[bool] {.nimcall, callback.}
+  FindProc = proc (db: RootRef, prefix: openArray[byte], onFind: KeyValueProc): KvResult[int] {.nimcall, callback.}
+  DelProc = proc (db: RootRef, key: openArray[byte]): KvResult[bool] {.nimcall, callback.}
+  ClearProc = proc (db: RootRef): KvResult[bool] {.nimcall, callback.}
+  ContainsProc = proc (db: RootRef, key: openArray[byte]): KvResult[bool] {.nimcall, callback.}
+  CloseProc = proc (db: RootRef): KvResult[void] {.nimcall, callback.}
 
   KvStoreRef* = ref object
     ## Key-Value store virtual interface
diff --git a/eth/db/kvstore_sqlite3.nim b/eth/db/kvstore_sqlite3.nim
index 0465d1e..9b3a67c 100644
--- a/eth/db/kvstore_sqlite3.nim
+++ b/eth/db/kvstore_sqlite3.nim
@@ -1,6 +1,11 @@
 ## Implementation of KvStore based on sqlite3
 
-{.push raises: [Defect].}
+when (NimMajor, NimMinor) < (1, 4):
+  {.push raises: [Defect].}
+  {.pragma: callback, gcsafe, raises: [Defect].}
+else:
+  {.push raises: [Defect].}
+  {.pragma: callback, gcsafe, raises: [].}
 
 import
   std/[os, options, strformat, typetraits],
@@ -22,7 +27,7 @@ type
   Sqlite* = ptr sqlite3
   SqliteStmt*[Params; Result] = distinct RawStmtPtr
   NoParams* = tuple # this is the empty tuple
-  ResultHandler*[T] = proc(val: T) {.gcsafe, raises: [Defect].}
+  ResultHandler*[T] = proc(val: T) {.callback.}
 
   SqStoreRef* = ref object
     # Handle for a single database - from here, keyspaces and statements
@@ -48,7 +53,7 @@ type
     proc (
       a: openArray[byte],
       b: openArray[byte]
-    ): Result[seq[byte], cstring] {.noSideEffect, gcsafe, cdecl, raises: [Defect].}
+    ): Result[seq[byte], cstring] {.noSideEffect, cdecl, callback.}
 
 template dispose(db: Sqlite) =
   discard sqlite3_close(db)
@@ -598,7 +603,7 @@ proc hasTable*(db: SqStoreRef, name: string): KvResult[bool] =
   let
     sql = "SELECT name FROM sqlite_master WHERE type='table' AND name='" &
       name & "';"
-  db.exec(sql, (), proc(_: openArray[byte]) = discard)
+  db.exec(sql, (), proc(_: openArray[byte]) {.callback.} = discard)
 
 proc openKvStore*(
     db: SqStoreRef, name = "kvstore", withoutRowid = false,
diff --git a/tests/db/test_kvstore_sqlite3.nim b/tests/db/test_kvstore_sqlite3.nim
index 9fbcc34..7feb9b3 100644
--- a/tests/db/test_kvstore_sqlite3.nim
+++ b/tests/db/test_kvstore_sqlite3.nim
@@ -249,7 +249,7 @@ procSuite "SqStoreRef":
 
   proc customSumFun(
     a: openArray[byte],
-    b: openArray[byte]): Result[seq[byte], cstring] {.noSideEffect, gcsafe, cdecl, raises: [Defect].} =
+    b: openArray[byte]): Result[seq[byte], cstring] {.cdecl.} =
     let num1 = uint32.fromBytesBE(a)
     let num2 = uint32.fromBytesBE(b)
     let sum = num1 + num2