diff --git a/constantine.nimble b/constantine.nimble
index 9a8efa8..d47ed2d 100644
--- a/constantine.nimble
+++ b/constantine.nimble
@@ -332,6 +332,7 @@ template setupCommand(): untyped {.dirty.} =
     # Not available in MinGW https://github.com/libressl-portable/portable/issues/54
     flags &= " --passC:-fstack-protector-strong"
   let command = "nim " & lang & cc & " -d:release " & flags &
+    " --panics:on " & # Defects are not catchable
     " --verbosity:0 --outdir:build/testsuite -r --hints:off --warnings:off " &
     " --nimcache:nimcache/" & path & " " &
     path
@@ -363,6 +364,7 @@ template setupBench(): untyped {.dirty.} =
   if not useAsm:
     cc &= " -d:CttASM=false"
   let command = "nim " & lang & cc &
+       " --panics:on " & # Defects are not catchable
        " -d:danger --verbosity:0 -o:build/bench/" & benchName & "_" & compiler & "_" & (if useAsm: "useASM" else: "noASM") &
        " --nimcache:nimcache/benches/" & benchName & "_" & compiler & "_" & (if useAsm: "useASM" else: "noASM") &
        runFlag & "--hints:off --warnings:off benchmarks/" & benchName & ".nim"
@@ -451,6 +453,7 @@ proc genDynamicBindings(bindingsName, prefixNimMain: string) =
     #             - heap-allocated strings for hex-string or decimal strings
     echo "Compiling dynamic library: bindings/generated/" & libName
     exec "nim c -f " & flags & " --noMain -d:danger --app:lib --gc:arc " &
+         " --panics:on " & # Defects are not catchable
          " --verbosity:0 --hints:off --warnings:off " &
          " --nimMainPrefix:" & prefixNimMain &
          " --out:" & libName & " --outdir:bindings/generated " &
@@ -481,6 +484,7 @@ proc genStaticBindings(bindingsName, prefixNimMain: string) =
     #             - heap-allocated strings for hex-string or decimal strings
     echo "Compiling static library:  bindings/generated/" & libName
     exec "nim c -f " & flags & " --noMain -d:danger --app:staticLib --gc:arc " &
+         " --panics:on " & # Defects are not catchable
          " --verbosity:0 --hints:off --warnings:off " &
          " --nimMainPrefix:" & prefixNimMain &
          " --out:" & libName & " --outdir:bindings/generated " &
diff --git a/constantine/ethereum_evm_precompiles.nim b/constantine/ethereum_evm_precompiles.nim
index f1f0907..1b88df9 100644
--- a/constantine/ethereum_evm_precompiles.nim
+++ b/constantine/ethereum_evm_precompiles.nim
@@ -114,8 +114,7 @@ func eth_evm_ecadd*(
 
   # Auto-pad with zero
   var padded: array[128, byte]
-  let lastIdx = min(inputs.len, 128) - 1
-  padded[0 .. lastIdx] = inputs.toOpenArray(0, lastIdx)
+  padded.copy(0, inputs, 0, min(inputs.len, 128))
 
   var P{.noInit.}, Q{.noInit.}, R{.noInit.}: ECP_ShortW_Prj[Fp[BN254_Snarks], G1]
 
@@ -171,8 +170,7 @@ func eth_evm_ecmul*(
 
   # Auto-pad with zero
   var padded: array[128, byte]
-  let lastIdx = min(inputs.len, 128) - 1
-  padded[0 .. lastIdx] = inputs.toOpenArray(0, lastIdx)
+  padded.copy(0, inputs, 0, min(inputs.len, 128))
 
   var P{.noInit.}: ECP_ShortW_Prj[Fp[BN254_Snarks], G1]