diff --git a/beacon_chain/validators/slashing_protection.nim b/beacon_chain/validators/slashing_protection.nim
index 43b58e3e8..0a6153eda 100644
--- a/beacon_chain/validators/slashing_protection.nim
+++ b/beacon_chain/validators/slashing_protection.nim
@@ -337,8 +337,8 @@ proc pruneBlocks*(
 proc pruneAttestations*(
        db: SlashingProtectionDB,
        validator: ValidatorPubkey,
-       newMinSourceEpoch: Epoch,
-       newMinTargetEpoch: Epoch) =
+       newMinSourceEpoch: int64,
+       newMinTargetEpoch: int64) =
   ## Prune all blocks from a validator before the specified newMinSlot
   ## This is intended for interchange import to ensure
   ## that in case of a gap, we don't allow signing in that gap.
diff --git a/beacon_chain/validators/slashing_protection_common.nim b/beacon_chain/validators/slashing_protection_common.nim
index 387e13252..3f3d25558 100644
--- a/beacon_chain/validators/slashing_protection_common.nim
+++ b/beacon_chain/validators/slashing_protection_common.nim
@@ -117,7 +117,7 @@ type
     # Pruning
     # --------------------------------------------
     db.pruneBlocks(ValidatorPubKey, Slot)
-    db.pruneAttestations(ValidatorPubKey, Epoch, Epoch)
+    db.pruneAttestations(ValidatorPubKey, int64, int64)
     db.pruneAfterFinalization(Epoch)
 
     # Interchange
@@ -446,4 +446,8 @@ proc importInterchangeV5Impl*(
 
     # Now prune everything that predates
     # this interchange file max slot
-    db.pruneAttestations(parsedKey, Epoch maxValidSourceEpochSeen, Epoch maxValidTargetEpochSeen)
+    if maxValidSourceEpochSeen < 0 or maxValidTargetEpochSeen < 0:
+      doAssert maxValidSourceEpochSeen == -1 and maxValidTargetEpochSeen == -1
+      notice "No attestation found in slashing interchange file"
+      return
+    db.pruneAttestations(parsedKey, maxValidSourceEpochSeen, maxValidTargetEpochSeen)
diff --git a/beacon_chain/validators/slashing_protection_v1.nim b/beacon_chain/validators/slashing_protection_v1.nim
index 920ee909c..d35987d79 100644
--- a/beacon_chain/validators/slashing_protection_v1.nim
+++ b/beacon_chain/validators/slashing_protection_v1.nim
@@ -955,16 +955,19 @@ proc pruneBlocks*(db: SlashingProtectionDB_v1, validator: ValidatorPubkey, newMi
 proc pruneAttestations*(
        db: SlashingProtectionDB_v1,
        validator: ValidatorPubkey,
-       newMinSourceEpoch: Epoch,
-       newMinTargetEpoch: Epoch) =
+       newMinSourceEpoch: int64,
+       newMinTargetEpoch: int64) =
   ## Prune all blocks from a validator before the specified newMinSlot
   ## This is intended for interchange import.
   ##
   ## Note: the Database v1 does not support pruning.
+  ##
+  ## Negative source/target epoch of -1 can be received if no attestation was imported
+  ## In that case nothing is done
   warn "Slashing DB pruning is not supported on the v1 of our database. Request ignored.",
     validator = shortLog(validator),
-    newMinSourceEpoch = shortLog(newMinSourceEpoch),
-    newMinTargetEpoch = shortLog(newMinTargetEpoch)
+    newMinSourceEpoch = newMinSourceEpoch,
+    newMinTargetEpoch = newMinTargetEpoch
 
 proc pruneAfterFinalization*(
        db: SlashingProtectionDB_v1,
diff --git a/beacon_chain/validators/slashing_protection_v2.nim b/beacon_chain/validators/slashing_protection_v2.nim
index 9d3337a7c..337523a6f 100644
--- a/beacon_chain/validators/slashing_protection_v2.nim
+++ b/beacon_chain/validators/slashing_protection_v2.nim
@@ -1020,14 +1020,16 @@ proc pruneBlocks*(db: SlashingProtectionDB_v2, validator: ValidatorPubkey, newMi
 proc pruneAttestations*(
        db: SlashingProtectionDB_v2,
        validator: ValidatorPubkey,
-       newMinSourceEpoch: Epoch,
-       newMinTargetEpoch: Epoch) =
+       newMinSourceEpoch: int64,
+       newMinTargetEpoch: int64) =
   ## Prune all blocks from a validator before the specified newMinSlot
   ## This is intended for interchange import.
+  ## Negative source/target epoch of -1 can be received if no attestation was imported
+  ## In that case nothing is done (since we used signed int in SQLite)
   let valID = db.getOrRegisterValidator(validator)
 
   let status = db.sqlPruneValidatorAttestations.exec(
-    (valID, int64 newMinSourceEpoch, int64 newMinTargetEpoch))
+    (valID, newMinSourceEpoch, newMinTargetEpoch))
   doAssert status.isOk(),
     "SQLite error when pruning validator attestations: " & $status.error & "\n" &
     "for validator: 0x" & validator.toHex() &