diff --git a/testmodule/test.nim b/testmodule/test.nim
index fcafd80..42d8371 100644
--- a/testmodule/test.nim
+++ b/testmodule/test.nim
@@ -9,5 +9,6 @@ import ./testErc20
 import ./testGasEstimation
 import ./testErrorDecoding
 import ./testCustomErrors
+import ./testBlockTag
 
 {.warning[UnusedImport]:off.}
diff --git a/testmodule/testBlockTag.nim b/testmodule/testBlockTag.nim
new file mode 100644
index 0000000..1e16518
--- /dev/null
+++ b/testmodule/testBlockTag.nim
@@ -0,0 +1,56 @@
+import std/unittest
+import std/strformat
+
+import pkg/stint
+import pkg/questionable
+
+import ethers/blocktag
+
+
+type
+  PredefinedTags = enum earliest, latest, pending
+
+suite "BlockTag":
+  for predefinedTag in PredefinedTags:
+    test fmt"can be created with predefined special type: {predefinedTag}":
+      var blockTag: BlockTag
+      case predefinedTag:
+      of earliest: blockTag = BlockTag.earliest
+      of latest: blockTag = BlockTag.latest
+      of pending: blockTag = BlockTag.pending
+      check $blockTag == $predefinedTag
+    
+  test "can be created with a number":
+    let blockTag = BlockTag.init(42.u256)
+    check blockTag.number == 42.u256.some
+
+  test "can be converted to string in hex format for BlockTags with number":
+    let blockTag = BlockTag.init(42.u256)
+    check $blockTag == "0x2a"
+
+  test "can be compared for equality when BlockTag with number":
+    let blockTag1 = BlockTag.init(42.u256)
+    let blockTag2 = BlockTag.init(42.u256)
+    let blockTag3 = BlockTag.init(43.u256)
+    check blockTag1 == blockTag2
+    check blockTag1 != blockTag3
+  
+  for predefinedTag in [BlockTag.earliest, BlockTag.latest, BlockTag.pending]:
+    test fmt"can be compared for equality when predefined tag: {predefinedTag}":
+      case $predefinedTag:
+      of "earliest":
+        check predefinedTag == BlockTag.earliest
+        check predefinedTag != BlockTag.latest
+        check predefinedTag != BlockTag.pending
+      of "latest":
+        check predefinedTag != BlockTag.earliest
+        check predefinedTag == BlockTag.latest
+        check predefinedTag != BlockTag.pending
+      of "pending":
+        check predefinedTag != BlockTag.earliest
+        check predefinedTag != BlockTag.latest
+        check predefinedTag == BlockTag.pending
+  
+  for predefinedTag in [BlockTag.earliest, BlockTag.latest, BlockTag.pending]:
+    test fmt"number accessor returns None for BlockTags with string: {predefinedTag}":
+      check predefinedTag.number == UInt256.none